雅思写作实用小语法：number的使用

　　1 Adjective forms

　　When expressions of measurement, amount and quantity are used as adjectives, they are normally singular. 当度量单位，数量等被用作形容词时，通常用单数形式。如：

　　a ten-mile walk

　　a twenty-pound note

　　a thirty-year period

　　ten two-hour lessons

　　Possessives are often used in expressions of time.在时间的表述中，经常用所有格。

　　a weeks holiday

　　two hours delay

　　2 hundred, thousand, dozen, etc

　　Typical mistake: she had at least four hundreds of lovers.

　　When these words are used after a number or several, they do not have s and of is not used. 当这些词用在一个数字，或者several后面时，不要加s也不要用of. 如：

　　She had at least four hundred lovers.

　　It cost several thousand pounds.

　　In other cases, the plural form is hundreds, dozens ,etc. 在其他情况下，用复数形式，后面通常跟着of. 如：

　　Ive seen it hundreds of times.

　　But youve got dozens of dresses.

　　3 half

　　Typical mistakes:

　　Only half us could come.

　　I live half of a mile from here.

　　Give me the half.

　　Half can be used before a noun, with or without of .

　　在名词前面，half可以跟of连用，也可以单独使用。

　　More than half my friends are foreigners.

　　She spends half her time traveling.

　　Before a personal pronoun, half of is always used.

　　在人称代词前面，通常用half of。

　　Can I have my records back?- ok, but Ive only had time to listen to half of them.

　　Only half of us could come last Tuesday.

　　Of is not used with half when we are talking about measurements or quantities.

　　当谈到度量或者数量时，half 后面不可以用of.

　　My old home is about half a mile from here.

　　Half a dozen eggs and half a pound of butter,please.

　　Cecily drank half a bottle of Scotch last night.

　　The expression one and a half is followed by a plural noun.

　　one and a half 后面用复数名词。

　　Ive been waiting for one and a half hours.

　　Half can be used as a pronoun, with no following noun. The article the is only used before half if there are adjectives or other words which say exactly which half we are talking about. Compare:

　　Half 可以用作代词，后面不跟名词。只有当我们明确知道说的是哪个half的情况下，才可以在half前面加冠词the.

　　I gave her half, and kept half for myself.

　　I gave her half, and kept the other half for myself.