both,either,neither都是不定代词,使用的范围都是两者之间。
(1)both指”两者都”,是对两者的肯定,修饰复数名词,如:
Both his father and mother are here.他们的父母都在这儿.
Both of them are good teachers.他们两个都是好老师.
They both skate well.他们两个都很会滑冰.
The children were both too young.这两个孩子都很年轻.
My parents have both been invited.我的父母都被邀请了.
(2)either表示”两者中任何一个”,可以指代或修饰单数名词,做主语时,谓语动词用单数形式,还可以和or搭配,如:
Either book is OK.teacheray.com两本书都可以.
There is a path on either side of the road.路的两边各有一条小道.
(3)neither表示”两者都不”,是对两者的否定,反义词是both,neither可以和nor搭配.如:
Neither answer is right.两个答案都不对.
Neither of my parents has ever read the book.我父母都没读过这本书.
需要注意的是:either…or…(要么…要么…),neither…nor…(既不…也不…)结构做主语时,谓语动词要与or或nor后面的成分在人称和数上保持一致,也就是我们常说的主谓一致就近原则.如:
Either you or I am right.=Either I or you are right.要么我对,要么你对.
Neither he nor we have been to NY.=Neither we nor he has been to NY.他和我们都没去过纽约.