This page uses content from Wikipedia and is licensed under CC BY-SA.
Measure words denote a unit or measurement and are used with mass nouns (uncountable nouns), and in some cases also with count nouns. For instance, in English, mud is a mass noun and thus one cannot say "three muds", but one can say "three drops of mud", "three pails of mud", etc. In these examples, drops and pails function as measure words. One can also say "three pails of shells"; in this case the measure word pails accompanies a count noun (shells).
The term measure word is also sometimes used to refer to numeral classifiers, which are used with count nouns in some languages. For instance, in English no extra word is needed when saying "three people", but in many East Asian languages a numeral classifier is added, just as a measure word is added for uncountable nouns in English. For example, to say one dog and three dogs in Chinese, one would need to say yīzhīgǒu (simplified 一只狗, traditional 一隻狗) and sānzhīgǒu (simplified 三只狗, traditional 三隻狗) respectively, which could be transliterated as one animal dog and three animal dog respectively. While many linguists maintain a distinction between measure words and numeral classifiers, the terms are sometimes used interchangeably. For instance, materials for teaching Chinese as a second language generally refer to Chinese classifiers as "measure words". The corresponding Chinese term is liàngcí (simplified Chinese: 量词; traditional Chinese: 量詞), which can be directly translated as "quantity word".
Though similar in construction, fractions are not measure words. For example, in "seven eights of an apple" the fraction acts as a noun. Compare that to "seven slices of apple" where "apple" is a mass noun and does not require the article "an". Combining the two, e.g. "seven-eighths of a slice of apple", makes it clear the fraction must be a noun referring to a part of another countable noun.
In many languages, including the East Asian languages referred to above, the analogous constructions do not include any equivalent of the English of. In German, for example, ein Glas Bier means "a glass [of] beer". This is interesting since both languages are West Germanic languages, making them closely related to each other. However, the equivalent of the English of is common in Romance languages such as Spanish, French, and Portuguese. In Spanish "a glass of beer" is "un vaso de cerveza", in French it is "un verre de bière", and in Portuguese it is "um copo de cerveja".