代词
1.不定代词(all , both, every, each, either, neither, more, little, few, much, many, another, other, some, any , one, no 以及some, something, anything, everything, somebody/one, anybody, anyone, nothing , nobody, no one, none, everybody/one.等。) 可作主语，当作主语时，要明确这一不定代词究竟是单数还是复数，以确定它和谓语动词在人和数的一致。
Someone is waiting for you at the school gate, but I have no idea who they are.
All 的主谓一致：all的单复数由它所修饰或指代的名词的单复数决定。不说 all the book，而说 the whole book。
但all可与表时间的可数名词单数连用，如 all day，all night，all the year；但习惯上不说 all hour，all century。all China，all the city，all my life，all the way
both, all 都可作同位语，其位置在行为动词前be 动词之后。如果助动词或情态动词后面的实义动词省去，则位于助动词或情态动词之前。
2.不定代词还可作定语。当作定语时，应该注意其所修饰的名词是可数还是不可数，以确定这个名词用单数还是复数。
例:1) Much has been done to fight pollution； 2) Each of them has got a present.
3) He said something was lost, but he didn’t say what it was.
Anything but绝对不. nothing but只有，只不过。None but除非；all but几乎，差不多 everything but除了
