While the spelling of Dutch is officially standardised by an international organisation (the Dutch Language Union), the pronunciation has no official standard and relies on a de facto standard documented in reference works such as The Phonetics of English and Dutch by Beverley Collins and Inger M. Mees,The Phonology of Dutch by Geert Booij,Dutch by Carlos Gussenhoven,Belgian Standard Dutch by Jo Verhoeven or pronunciation dictionaries such as Uitspraakwoordenboek ("Pronunciation Dictionary") by Josée Heemskerk and Wim Zonneveld.
Standard Dutch has two main de facto pronunciation standards: Northern and Belgian. Northern Standard Dutch (henceforth Northern SD) is the most prestigious accent in the Netherlands. It is associated with high status, education and wealth. Even though its speakers seem to be concentrated in the provinces of North Holland, South Holland and Utrecht (especially in the Randstad), it cannot be considered a regional dialect. It is often impossible to tell where its speakers were born or brought up. Belgian Standard Dutch (henceforth Belgian SD) is used by the vast majority of Flemish journalists, which is why it is sometimes called VRT-Nederlands ("VRT Dutch"; formerly BRT-Nederlands "BRT Dutch"), after VRT, the national public-service broadcaster for the Flemish Region.
/ɡ/ is not a native phoneme of Dutch and occurs only in borrowed words, like goal. In native words, [ɡ] occurs as an allophone of /k/ when it undergoes voicing assimilation, like in zakdoek[ˈzɑɡduk].
In the north, /ɣ/ often devoices and merges with /x/; the quality of that merged sound has been variously described as:
Voiceless post-velar trill fricative [ʀ̝̊˖] which, before /j/, can be fronted to [ç];
Voiceless post-velar [x̠] or uvular [χ] fricative.
In the south, the distinction between /x/ and /ɣ/ is generally preserved as velar [x, ɣ] or post-palatal [x̟, ɣ˖]. Some southern speakers may alternate between the velar and post-palatal articulation, depending on the backness of the preceding or succeeding vowel. Velar, post-velar and uvular variants are called harde g "hard g", while the post-palatal variants are called zachte g "soft g". There is also a third variant called zwakke harde g "weak hard g", in which /ɣ/ is realized as [ɦ] and /x/ is realized as [h] and is used in Zeeland and West Flanders, which are h-dropping areas, so that /ɦ/ does not merge with glottal variants of /ɣ/ and /x/.
In the Netherlands, /v/ can devoice and merge with /f/. According to Collins & Mees (2003), there are hardly any speakers of Northern SD who consistently contrast /v/ with /f/.
In low-prestige varieties of Netherlandic Dutch (such as the Amsterdam accent) also /z/ can devoice and merge with /s/.
Speakers who devoice /v/ and /z/ may also hypercorrectively voice /f/ and /s/: concert "concert" may thus be [kɔnˈzɛrt] compared to the more usual [kɔnˈsɛrt].
Some speakers pronounce /ɦ/ as a voiceless [h]. Some dialects, particularly those from the southwest, exhibit h-dropping.
In the Netherlands, /s/ and /z/ may have only mid-to-low pitched friction, and for many Netherlandic speakers, they are retracted. In Belgium, they are more similar to English /s, z/.
The sequences /sj/ and /zj/ are often assimilated to palatalised [sʲ, zʲ], alveolo-palatal[ɕ, ʑ], postalveolar[ʃ, ʒ] or similar realisations.
The sequences /tj/ and /dj/ are assimilated to [c] intervocalically and after /n/ unless they're at the beginning of a stressed syllable, barring loanwords and some names.
/ʃ, ʒ/ are not native phonemes of Dutch and usually occur only in borrowed words, like show and bagage "baggage". Depending on the speaker and the position in the word, they may or may not be distinct from the assimilated realisations of the clusters /sj, zj/. If they are not distinct, they will have the same range of realisations noted above.
/m/ and /n/ assimilate their articulation to a following obstruent in many cases:
Both become [m] before /p, b/, and [ɱ] before /f, v/.
/n/ merges into /ŋ/ before velars (/k, ɡ, x, ɣ/). The realisation of /ŋ/, in turn, depends on how a following velar fricative is realised. For example, it will be uvular [ɴ] for speakers who realise /x, ɣ/ as uvulars.
/n/ is realised as [ɲ] before /j/. That occurs also before /ʃ/ or /ʒ/ and, under assimilation, before /sj/ and /zj/.
The exact pronunciation of /l/ varies regionally:
In the North, /l/ is 'clear' before vowels and 'dark' before consonants and pauses. Intervocalic /l/ tends to be clear except after the open back vowels /ɔ, ɑ/. However, some speakers use the dark variant in all intervocalic contexts.
Some accents, such as the Amsterdam and the Rotterdam ones, have dark /l/ in all positions. Conversely, some accents in the eastern regions, along the German border (for example around Nijmegen), as well as some Standard Belgian speakers, have clear /l/ in all contexts.
The quality of dark /l/ varies; in the North it is pharyngealized[lˤ], but in a final position, many speakers produce a strongly pharyngealized vocoid with no alveolar contact ([ɤˤ]) instead. In Belgium, it is either velarized [lˠ] or post-palatalized [lʲ̠].
The realization of /r/ phoneme varies considerably from dialect to dialect and even between speakers in the same dialect area:
The uvular trill[ʀ] is a common alternative, found particularly in the central and southern dialect areas. Uvular pronunciations appear to be gaining ground in the Randstad. Syllable-finally, it may be debuccalized to [ɐ], much as in German. This is more common in the (south)eastern areas (Limburg, southeast Brabantian, Overijssel).
An epenthetic [ə] may be inserted between /l, r/ and word-final /m, n, p, k, f, x/. Thus melk/mɛlk/ "milk" may be pronounced [ˈmɛlək]. This may extend to compounds, e.g. melkboer[ˈmɛləkbuːr] "milkman". Although this pronunciation is mistakenly thought of as non-standard, it is found in all types of Dutch, including the standard varieties. There is also another type of [ə]-insertion that occurs word-medially (e.g. helpen[ˈɦɛləpə] "to help"), which is considered non-standard.
In many areas the final 'n' of the ending -en (originally /ən/, with a variety of meanings) is pronounced only when a word is being individually stressed; this makes -en words homophonous with otherwise identical forms ending in -e alone. The -n is dropped both word-finally and, in compound words, word-internally. This pronunciation can be morphologically sensitive and serve to distinguish words, since the -n is dropped only when it is part of the distinct ending -en and not when the word consists of an indivisible stem which happens to end in -en. Thus, the teken of ik teken ('I draw') always retains its -n because it is part of an indivisible stem whereas in teken ('ticks') it is dropped because it is part of a plural ending. Such pairs (teken = 'draw'; teken = 'ticks') are therefore not homophones in dialects that drop -n, despite being written identically.
Final -n is retained in the North East (Low Saxon) and the South West (East and West Flemish), where it is the schwa that disappears instead. This creates a syllabic [n] or (after velars) syllabic [ŋ] sounds: laten[ˈlaːtn̩]; maken[ˈmaːkŋ̍]. Some Low Saxon dialects that have uvular pronunciations of /ɣ/ and /x/ (or one of them) also have a syllabic uvular nasal, like in lagen and/or lachen[ˈlaːχɴ̩]
Final devoicing and assimilation
Dutch devoices all obstruents at the ends of words, as is partly reflected in the spelling. The voiced "z" in plural huizen[ˈɦœy̑zə] becomes huis[ɦœy̑s] ('house') in singular. Also, duiven[ˈdœy̑və] becomes duif[dœy̑f] ('dove'). The other cases are always written with the voiced consonant, but a devoiced one is actually pronounced: the "d" in plural baarden[ˈbaːrdə] is retained in singular spelling baard ('beard'), but the pronunciation of the latter is [baːrt], and plural ribben[ˈrɪbə] has singular rib ('rib'), pronounced [rɪp].
Dutch has an extensive vowel inventory consisting of thirteen plain vowels and at least three diphthongs. Vowels can be grouped as front unrounded, front rounded, central and back. They are also traditionally distinguished by length or tenseness. The vowels /eː, øː, oː/ are included in one of the diphthong charts further below because Northern SD realizes them as diphthongs, but they behave phonologically like the other long monophthongs.
Monophthongs of Belgian SD, from Verhoeven (2005:245). The schwa /ə/ is not shown.
Dutch allophones of unrounded monophthongs, from Collins & Mees (2003:92, 130, 132, 134). Black vowels occur before /r/ in Northern SD and Randstad Dutch, and the red vowel occurs before the dark /l/.
Dutch allophones of rounded monophthongs, from Collins & Mees (2003:98, 130, 132, 134). Black vowels occur before /r/ in Northern SD and Randstad Dutch, and the blue vowel occurs before /ŋ/.
Dutch vowels can be classified as lax and tense, checked and free or short and long. Phonetically however, the close vowels /i, y, u/ are as short as the phonological lax/short vowels unless they occur before /r/.
Phonologically, /ɪ, ʏ, ʊ/ can be classified as either close or close-mid. Carlos Gussenhoven classifies them as the former, whereas Geert Booij says that they are the latter and classifies /ɛ, ɔ/ and the non-native mid vowels as open-mid.
/ʏ/ has been traditionally transcribed with ⟨œ⟩, but modern sources tend to use ⟨ʏ⟩ or ⟨ɵ⟩ instead. Beverley Collins and Inger Mees write this vowel with ⟨ʉ⟩.
The phonemic status of /ʊ/ is not clear. Phonetically, a vowel of the [ʊ̞ ~ ɔ̽] type appears before nasals as an allophone of /ɔ/, e.g. in jong[jʊŋ] ('young'). This vowel can also be found in certain other words, such as op[ʊp] ('on'), which can form a near-minimal pair with mop[mɔp] ('joke'). This, however, is subject to both individual and geographical variation.
Many speakers feel that /ə/ and /ʏ/ belong to the same phoneme, with [ə] being its unstressed variant. This is reflected in spelling errors produced by Dutch children, for example ⟨binnu⟩ for binnen[ˈbɪnə(n)] ('inside'). Adding to this, the two vowels have different phonological distribution; for example, /ə/ can occur word-finally, while /ʏ/ (along with other lax vowels) cannot. In addition, the word-final allophone of /ə/ is a close-mid front vowel with some rounding [ø̜], a sound that is similar to /ʏ/.
The native tense vowels /eː, øː, oː, aː/ are long [eː, øː, oː, aː] in stressed syllables and short [e, ø, o, a] elsewhere. The non-native oral vowels appear only in stressed syllables and thus are always long.
The native /eː, øː, oː, aː/ as well as the non-native nasal /ɛ̃ː, œ̃ː, ɔ̃ː, ɑ̃ː/ are sometimes transcribed without the length marks, as ⟨e, ø, o, a, ɛ̃, œ̃, ɔ̃, ɑ̃⟩.
The non-native /iː, yː, uː, ɛː, œː, ɔː, ɑː/ occur only in stressed syllables. In unstressed syllables, they are replaced by the closest native vowel. For instance, verbs corresponding to the nouns analyse/aːnaːˈliːzə/ ('analysis'), centrifuge/sɛntriˈfyːzjə/ ('spinner'), and zone/ˈzɔːnə/ ('zone') are analyseren/aːnaːliˈzeːrən/ ('to analize'), centrifugeren/sɛntrifyˈɣeːrən/ ('to spin-dry'), and zoneren/zoːˈneːrən/ ('to divide into zones').
/œː/ is extremely rare, and the only words of any frequency in which it occurs are oeuvre[ˈœːvrə], manoeuvre[maˈnœːvrə] and freule. In the more common words, /ɛː/ tends to be replaced with the native /ɛ/, whereas /ɔː/ can be replaced by either /ɔ/ or /oː/ (Belgians typically select the latter).
The non-native nasal vowels /ɛ̃ː, œ̃ː, ɔ̃ː, ɑ̃ː/ occur only in loanwords from French./ɛ̃ː, ɔ̃ː, ɑ̃ː/ are often nativized as /ɛn, ɔn, ɑn/, /ɛŋ, ɔŋ, ɑŋ/ or /ɛm, ɔm, ɑm/, depending on the place of articulation of the following consonant. For instance, restaurant/rɛstoːˈrɑ̃ː/ ('restaurant') and pardon/pɑrˈdɔ̃ː/ ('excuse me') are often nativized as /rɛstoːˈrɑnt/ and /pɑrˈdɔn/, respectively./œ̃ː/ is extremely rare, just like its oral counterpart and the only word of any frequency in which it occurs is parfum/pɑrˈfœ̃ː/ ('perfume'), often nativized as /pɑrˈfʏm/ or /ˈpɑrfʏm/.
The non-native /ɑː/ is listed only by some sources. It occurs in words such as cast/kɑːst/ ('cast').
The following sections describe the phonetic quality of Dutch monophthongs in detail.
/ɪ/ is close to the canonical value of the IPA symbol ⟨ɪ⟩. The Standard Belgian realization has also been described as close-mid [ɪ̞]. In regional SD, the realization may be different: for example, in Antwerp it is closer, more like [i], whereas in places like Dordrecht, Nijmegen, West and East Flanders the vowel is typically more open than the SD counterpart, more like [ë]. Affected speakers of Northern SD may also use this vowel.
The majority of sources consider /ʏ/ to be close-mid central [ɵ], yet Beverley Collins and Inger Mees consider it to be close-mid front [ʏ̞]. The study conducted by Vincent van Heuven and Roos Genet has shown that native speakers consider the canonical IPA value of the symbol ⟨ɵ⟩ to be the most similar to the Dutch sound, much more similar than the canonical values of ⟨ʏ⟩ and ⟨œ⟩ (the sound represented by ⟨ʉ⟩ was not a part of the study). In regional SD /ʏ/ may be raised to near-close [ɵ̝], for example in Amsterdam, Rotterdam and The Hague. In Antwerp, the vowel may be as high as /y/ and the two vowels may differ in nothing but length. A more open vowel of the [ɵ̞]-type is found in southern accents (e.g. in Bruges) and in affected Northern SD.
/y, yː/ have been variously described as close front [y, yː], near-close front [y˕, y˕ː] and, in Northern SD, near-close central [ʉ̞, ʉ̞ː].
/u, uː/ are close back [u, uː] in Northern SD and close near-back [u̟, u̟ː] in Belgian SD and some varieties of regional SD spoken in Antwerp and Flemish Brabant.
Word-final /i, y, u/ are raised and end in a voiceless vowel: [ii̥, yẙ, uu̥]. The voiceless vowel in the first sequence may sound almost like a palatal fricative [ç].
/i, y, u/ are frequently longer in Belgian SD and most Belgian accents than in Northern SD, in which the length of these vowels is identical to that of lax vowels.
Regardless of the exact accent, /i, y, u/ are mandatorily lengthened to [iː, yː, uː] before /r/ in the same word. In Northern SD and in Randstad, these are laxed to [i̽ː, y˕ː, u̽ː] and often have a schwa-like off-glide ([i̽ə, y˕ə, u̽ə]). This means that before /r/, /i, y, u/ are less strongly differentiated from /eː, øː, oː/ in Northern SD and Randstad than is usually the case in other regional varieties of SD and in Belgian SD. There is one exception to the lengthening rule: when /r/ is followed by a consonant different than /t/ and /s/, /i, y, u/ remain short. Examples of that are words such as wierp[ʋirp], stierf[stirf], zwierf[zʋirf], bedierf[bəˈdirf], kirsch[kirʃ] and Atatürk[ˈaːtaˌtyrk]. The rule is also suppressed syllable-finally in certain compounds; compare roux-room[ˈruroːm] with roerroom[ˈruːr(r)oːm] and Ruhr-Ohm[ˈruːroːm].
/ɛ, ɛː/ are open-mid front [ɛ, ɛː]. According to Jo Verhoeven, the Belgian SD variants are somewhat raised. Before /n/ and the velarized or pharyngealized allophone of /l/, /ɛ/ is typically lowered to [æ]. In some regional SD (e.g. in Dordrecht, Ghent, Bruges and more generally in Zeeland, North Brabant and Limburg), this lowering is generalized to most or even all contexts. Conversely, some regional SD varieties (e.g. much of Randstad Dutch, especially the Amsterdam dialect as well as the accent of Antwerp) realize the main allophone of /ɛ/ as higher and more central than open-mid front ([ɛ̝̈]).
/ə/ has two allophones, with the main one being mid central unrounded [ə]. The allophone used in word-final postions resembles the main allophone of /ʏ/ as it is closer, more front and more rounded ([ø̜]).
/ɔ/ is a very tense, pharyngealized vowel. Its backness has been described as back [ɔˤ] by Collins and Mees and near-back [ɔ̟ˤ] by Gussenhoven and Verhoeven. The pharyngeal effect is more pronounced in Northern SD than in the standard Belgian variety. /ɔː/ is close to /ɔ/ in terms of height and backness, but it is unclear whether it is has the same secondary articulation of pharyngealization.
/ɛ, ɔ/ are typically somewhat lengthened and centralized before /r/ in Northern SD and Randstad, usually with a slight schwa-like offglide: [ɛ̈ə̆, ɔ̈ə̆]. In addition, /ɔ/ in this position is somewhat less rounded ([ɔ̜̈ə̆]) than the main allophone of /ɔ/.
The free vowels /eː, øː, oː/ are realized as monophthongs [eː, øː, oː] in Belgian SD (Jo Verhoeven describes the Belgian SD realization of /øː/ as mid central [ɵ̞ː]) and in many regional accents. In Northern SD, narrow closing diphthongs [eɪ, øʏ, oʊ] are used. The starting point of [oʊ] is centralized back ([ö]), and the starting point of [eɪ] has been described as front [e] by Collins and Mees and as centralized front [ë] by Gussenhoven. The monophthongal counterparts of [eɪ, oʊ] are peripheral; the former is almost as front as cardinal [eː], whereas the latter is almost as back as cardinal [oː]. Many speakers of Randstad Dutch as well as younger speakers of Northern SD realize /eː, øː, oː/ as rather wide diphthongs of the [ɛɪ, œʏ, ɔʊ] type, which may be mistaken for the phonemic diphthongs /ɛi, œy, ɔu/ by speakers of other accents. Using [ɛɪ, œʏ, ɔʊ] for /eː, øː, oː/ goes hand in hand with lowering the first elements of /ɛi, œy, ɔu/ to [aɪ, aʏ, aʊ], a phenomenon termed Polder Dutch. Therefore, the phonemic contrast between /eː, øː, oː/ and /ɛi, œy, ɔu/ is still strongly maintained, but its phonetic realization is very different from what one can typically hear in traditional Northern SD. In Rotterdam and The Hague, the starting point of [oʊ] can be fronted to [ə] instead of being lowered to [ɔ].
In Northern SD and in Randstad, /eː, øː, oː/ lose their closing glides and are raised and slightly centralized to [ɪː, ʏː, ʊː] (often with a schwa-like off-glide [ɪə, ʏə, ʊə]) before /r/ in the same word. The first two allophones strongly resemble the lax monophthongs /ɪ, ʏ/. Dutch children frequently misspell the word weer ('again') as wir. These sounds may also occur in regional varieties of SD and in Belgian SD, but they are more typically the same as the main allophones of /eː, øː, oː/ (that is, [eː, øː, oː]). An exception to the centralizing rule are syllable-final /eː, øː, oː/ in compounds such as zeereis[ˈzeɪˌrɛis] ('sea voyage'), milieuramp[mɪlˈjøʏˌrɑmp] ('environmental disaster') and bureauredactrice[byˈroʊredɑkˌtrisə] ('desk editor (f.)').
In Northern SD, /eː, øː, oː/ are mid-centralized before the pharyngealized allophone of /l/.
Several non-standard dialects have retained the distinction between the so-called "sharp-long" and "soft-long" e and o, a distinction that dates to early Middle Dutch. The sharp-long varieties originate from the Old Dutch long ē and ō (Proto-Germanic ai and au), while the soft-long varieties arose from short i/e and u/o that were lengthened in open syllables in early Middle Dutch. The distinction is not considered to be a part of Standard Dutch and is not recognised in educational materials, but it is still present in many local varieties, such as Antwerpian, Limburgish, West Flemish and Zealandic. In these varieties, the sharp-long vowels are often opening diphthongs such as [ɪə, ʊə], while the soft-long vowels are either plain monophthongs [eː, oː] or slightly closing [eɪ, oʊ].
In Northern SD and some other accents, /ɑ, aː/ are realised so that the former is a back vowel [ɑ], whereas the latter is central [äː] or front [aː]. In Belgian SD /aː/ is also central or front, but /ɑ/ may be central [ä] instead of back [ɑ], so it may have the same backness as /aː/.
Other accents may have different realisations:
Many accents (Amsterdam, Utrecht, Antwerp) realize this pair with 'inverted' backness, so that /ɑ/ is central [ä] (or, in the case of Utrecht, even front [a]), whereas /aː/ is closer to cardinal [ɑː].
Outside the Randstad, fronting of /ɑ/ to central [ä] is very common. On the other hand, in Rotterdam and Leiden, the short /ɑ/ sounds even darker than the Standard Northern realization, being realized as a fully back and raised open vowel, unrounded [ɑ̝] or rounded [ɒ̝].
In Groningen, /aː/ tends to be particularly front, similar to the quality of the cardinal vowel [aː], whereas in The Hague and in the affected Standard Northern accent, /aː/ may be raised and fronted to [æː], particularly before /r/.
Before /r/, /ɑ/ is typically a slight centering diphthong with a centralized first element ([ɐə̆]) in Northern SD and in Randstad.
Dutch also has several diphthongs, but only three of them are indisputably phonemic. All of them end in a non-syllabic close vowel [i̯, y̑, u̯] (henceforth written [i, y, u] for simplicity), but they may begin with a variety of other vowels.
/ɔu/ has been variously transcribed with ⟨ɔu⟩, ⟨ɑu⟩, and ⟨ʌu⟩.
The starting points of /ɛi, œy, ɔu/ tend to be closer ([ɛɪ, œ̈ʏ, ɔ̈ʊ]) in Belgian SD than in Northern SD ([ɛ̞ɪ, œ̞̈ʏ, ʌ̞̈ʊ]). In addition, the Belgian SD realization of /ɔu/ tends to be fully rounded, unlike the typical Northern SD realization of the vowel. However, Jo Verhoeven reports rather open starting points of the Belgian SD variants of /œy, ɔu/ ([œ̞̈ʏ, ɔ̞̈ʊ]), so the main difference between Belgian and Northern SD in that regard may be only in the rounding of the first element of /ɔu/, but the fully rounded variant of /ɔu/ is also used by some Netherlands speakers, particularly of the older generation. It is also used in most of Belgium, in agreement with the Belgian SD realization.
In conservative Northern SD, the starting points of /ɛi, œy, ɔu/ are open-mid and rounded in the case of the last two vowels: [ɛɪ, œʏ, ɔʊ].
The backness of the starting point of the Belgian SD realization of /ɛi/ has been variously described as front [ɛɪ] and centralized front [ɛ̈ɪ].
In Polder Dutch spoken in some areas of the Netherlands (especially Randstad and its surroundings), the starting points of /ɛi, œy, ɔu/ are further lowered to [aɪ, aʏ, aʊ] to facilitate the pronunciation. This typically goes hand in hand with lowering the starting points of /eː, øː, oː/ to [ɛɪ, œʏ, ɔʊ]. These realizations have existed in Hollandic dialects since the 16th century and now are becoming standard in the Netherlands. They are an example of a chain shift akin to the Great Vowel Shift. According to Jan Stroop, the fully lowered variant of /ɛi/ is the same as the phonetic diphthong [aːi], making bij 'at' and baai 'bay' perfect homophones.
The rounding of the starting point of the Northern SD realization of /œy/ has been variously described as slight [œ̜ʏ] and nonexistent [ɐ̜ʏ]. The unrounded variant has also been reported to occur in many other accents, for example Leiden, Rotterdam and in some Belgian speakers.
Phonetically, the ending points of the native diphthongs are lower and more central than cardinal [i, y, u], i.e. more like [ɪ, ʏ, ʊ] or even [e, ø, o] (however, Jo Verhoven reports a rather close ([ï]) ending point of the Belgian SD variant of /ɛi/, so this might be somewhat variable). In Belgian SD, the ending points are shorter than in Northern SD, but in both varieties the glide is an essential part of the articulation. Furthermore, in Northern SD there is no appreciable difference between the ending points of /ɛi, œy, ɔu/ and the phonetic diphthongs [eɪ, øʏ, oʊ], with both sets ending in vowels close to [ɪ, ʏ, ʊ].
In some regional varieties of SD (Southern, regional Belgian), the ending points of /ɛi, œy, ɔu/ are even lower than in Standard Dutch: [ɛe̞, œø̞, ɔo̞ ~ ʌo̞], and in the traditional dialect of The Hague they are pure monophthongs [ɛː, œː, ɑː]. Broad Amsterdam speakers can also monophthongize /ɛi/, but to [aː]. It typically does not merge with /aː/ as that vowel has a rather back ([ɑː]) realization in Amsterdam.
Apart from [eɪ, øʏ, oʊ] which occur only in Northern SD and regional Netherlands SD, all varieties of SD have phonetic diphthongs [iu, yu, ui, eːu, ɔi, oːi, ɑi, aːi]. Phonemically, they are considered to be sequences of /iʋ, yʋ, uj, eːʋ, ɔj, oːj, ɑj, aːj/ by Geert Booij and as monosyllabic sequences /iu, yu, ui, eːu, oːi, aːi/ by Beverley Collins and Inger Mees (they do not comment on [ɔi] and [ɑi]). This article adopts the former analysis.
In Northern SD, the second elements of [iu, yu, eːu] can be labiodental [iʋ, yʋ, eːʋ]. This is especially common in intervocalic positions.
In Northern SD and regional Netherlands SD, the close-mid elements of [eːu, oːi] may be subject to the same kind of diphthongization as /eː, oː/, so they may be actually triphthongs with two closing elements [eɪu, oʊi] ([eːu] can instead be [eɪʋ], a closing diphthong followed by [ʋ]). In Rotterdam, [oːi] can be phonetically [əʊi], with a central starting point.
[aːi] is realized with more prominence on the first element according to Booij and with equal prominence on both elements according to Collins and Mees. Other diphthongs have more prominence on the first element.
The ending points of these diphthongs are typically somewhat more central ([ï, ü]) than cardinal [i, u]. They tend to be higher than the ending points of the phonemic diphthongs /ɛi, œy, ɔu/.
Most native Germanic words (the bulk of the core vocabulary) are stressed on the root syllable, which is usually the first syllable of the word. Germanic words may also be stressed on the second or later syllable if certain unstressed prefixes are added (particularly in verbs). Non-root stress is common in loanwords, which are generally borrowed with the stress placement unchanged. In polysyllabic words, secondary stress may also be present. Certain prefixes and suffixes will receive secondary stress: /ˌvoːrˈkoːmən/, /ˈʋeːrˌloːs/. The stressed syllable of a word receive secondary stress within a compound word: /ˈbɔmˌmɛldɪŋ/, /ˈɑlkoːɦɔl pɛrsɛnˌtaːʒə/.
While stress is phonemic, minimal pairs are rare, and marking the stress in written Dutch is always optional, but it is sometimes recommended to distinguish homographs that differ only in stress. The most common practice is to distinguish een (indefinite article, which, as a clitic, bears no stress) from één (the cardinal number one). It also distinguishes some verbs, as stress placement on prefixes also carries a grammatical distinction, such as in vóórkomen ('to occur') and voorkómen ('to prevent'). In vóórkomen and other verbs with a stressed prefix, the prefix is separable and separates as kom voor in the first-person singular present, with the past participle vóórgekomen. On the other hand, verbs with an unstressed prefix are not separable: voorkómen becomes voorkóm in the first-person singular present, and voorkómen in the past participle, without the past participle prefix ge-.
Dutch has a strong stress accent like other Germanic languages, and it uses stress timing because of its relatively complex syllable structure. It has a preference for trochaic rhythm, with relatively stronger and weaker stress alternating between syllables in such a way that syllables with stronger stress are produced at a more or less constant pace. Generally, every alternate syllable before and after the primary stress will receive relative stress, as far secondary stress placements allow: Wá.gə.nì.ngən. Relative stress preferably does not fall on /ə/ so syllables containing /ə/ may disrupt the trochaic rhythm. To restore the pattern, vowels are often syncopated in speech: kín.də.rən > /ˈkɪn.drən/, há.ri.ngən > /ˈɦaːr.ŋən/, vər.gə.líj.king > /vər.ˈɣlɛi.kɪŋ/. In words for which the secondary stress is imposed lexically onto the syllable immediately following the stressed syllable, a short pause is often inserted after the stressed syllable to maintain the rhythm to ensure that the stressed syllable has more or less equal length to the trochaic unit following it: bóm..mèl.ding, wéér..lò.zə.
Historically, the stress accent has reduced most vowels in unstressed syllables to [ə], as in most other Germanic languages. This process is still somewhat productive, and it is common to reduce vowels to [ə] in syllables carrying neither primary nor secondary stress, particularly in syllables that are relatively weakly stressed due to the trochaic rhythm. Weakly stressed long vowels may also be shortened without any significant reduction in vowel quality. For example, politie (phonemically /poːˈlitsi/) may be pronounced [poˈli(t)si], [pəˈli(t)si] or even [ˈpli(t)si].
The syllable structure of Dutch is (C)(C)(C)V(C)(C)(C)(C). Many words, as in English, begin with three consonants such as straat (street). Words that end in four consonants are mostly superlative adjectives.
/-k-/ > /-x-/: German machen vs. Dutch maken (help·info), English make
/-p-/ > /-f-/: German Schaf vs. Dutch schaap (help·info), English sheep
/-t-/ > /-s-/: German Wasser vs. Dutch water (help·info), English water
/-θ-/ > /-d-/: German das, Dutch dat (help·info) vs. English that
Dutch generalised the fricative variety of Proto-Germanic */ɡ/ as [ɣ] or [ʝ], in contrast with German, which generalised the stop [ɡ], and English, which lost the fricative variety through regular sound changes.
/ft/ changed to /xt/ (phonetically [χt ~ xt ~ x̟t]), spelled ⟨cht⟩, but it was later reverted in many words by analogy with other forms. Compare English loft, German Luft, Dutch lucht (pronounced [lʏxt] (help·info) or [lʏx̟t] (help·info)).
Proto-Germanic */uː/ turned into /yː/ through palatalisation, which, in turn, became the diphthong /œy/ (help·info), spelled ⟨ui⟩. Long */iː/ also diphthongised to /ɛi/ (help·info), spelled ⟨ij⟩.
Gussenhoven, Carlos (1999). "Dutch". Handbook of the International Phonetic Association: A guide to the use of the International Phonetic Alphabet. Cambridge: Cambridge University Press. pp. 74–77. ISBN0-521-65236-7. Retrieved 25 March 2017.
Kloots, Hanne; de Schutter, Georges; Gillis, Steven; Swerts, Marc (2004). "Svarabhaktivokale im Standardniederländischen in Flandern und den Niederlanden". Zeitschrift für Dialektologie und Linguistik (in German). Franz Steiner Verlag. 71 (2): 129–155. JSTOR40505018.