4.both “(两者)都” ,作主语时,看作复数;作定语时,后跟名词复数。
either “两者中任何一个” ,作主语时,谓语用第三人称单数;作定语时,后跟名词单数。
neither “(两者)都不”,含有否定意义,用法同either。
如:①They
both swim well. =Both of them swim well.
②There
are trees on both sides of the street. = There are trees on either side of the
street.
③Neither
of us is going to Beijing next week.
④Neither
answer is right.