's s前的小逗点符号叫做"所有格符号 (apostrophe)"
我们使用所有格符号来产生所有格、省略字 (contractions) 和一些复数。所有格符号代表一个省略动词被省略了一个或数个字母：
例如:
she is = she's it is = it's let us = let's who is = who's
在所有格中，所有格符号的位置视该表示所有的名词为单数或复数而定。大体而言，如果名词是单数，那麼所有格符号位在 s 的前面：The witch's broom.如果名词是复数，则所有格符号位在 s 的后面：The witches' brooms. 然而，倘若该名词是没有 s 的复数化字，那麼所有格符号位在 s 的前面：He entered the men's room with an armload of children's clothing. 如果你是用类似 of the witches 的片语来产生所有格，那麼无须使用所有格符号：the brooms of the witches.
注: it's 是 it is 或 it has。it's 与 it 的所有格 its 的混淆，可能是写作时最常犯的错误。
所有格符号也被用来形成若干复数，尤其是字母或数字的复数：Raoul got four A's last term and his sister got four 6's in the Olympic ice-skating competition. 现今我们已不再使用所有格符号来产生年份或缩写字的复数，因为这已被视为不正确的写法：He wrote several novels during the 1930s. There are fifteen PhDs on our faculty. My sister and I have identical IQs.
it和was 不可以缩写!
"was/were" 和 "人称代名词" 没有缩写形态
but, "was/were" 和 "not" 可以缩写, was not= wasn't were not= weren't
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