1) both (两者都),either(两者中任何一个),neither (两者都不).以上词使用范围为两个人或物.
Neither of the two boys is clever.两个男孩都不聪明.
2) both,either
both与复数连用,either与单数连用.
Both the boys are clever.两个男孩都很聪明.
Either of the two boys is clever.两个男孩都很聪明.
There are flowers on both sides of the street.
(两岸)
There are flowers on either side of the street.
(岸的两边)
路边长满了野花.