both
1.下面四句意思相同：
- Both sisters are here. Both the sisters are here.（比较不普通）
- Both of the sisters are here. The sisters are both here.
the both sisters和the both of the sisters也有人说，但都不算正当。
2.Both sisters（或Both the sisters，或Both of the sisters）are not here或The sisters are not both here是“姐妹两人并不都在这里”，就是说“一个在这里，一个不在这里”，并不是“姐妹两人都不在这里”。Neither sister（或Neither of the sisters）is here才是“姐妹两人都不在这里”。
3.both ... and ...是习语，如both boys and girls。论理似乎只能指两项，但事实上并没有这种限制，如尽可说both boys and grils and men and women。
4.both ... and ...里的两个“…”最好是同性质的，如可以说both boys and girls，也可以说both with boys and with girls和with both boys and girls，但最好不说both with boys and girls。同样地，下面各种表达方式都最好不说：
- both the dog and cat (该说both the dog and the cat或both dog and cat),
- both his hands and feet (该说both his hands and his feet),
- both in China and the Soviet Union (该说both in China and in the Soviet Union或in both China and the Soviet Union),
- both because of ill health and the cold weather (该说both because of ill health and because of the cold weather, because both of ill health and of the cold weather或because of both ill health and the cold weather)
5.He knows both English and German比He knows English and German both普通。
6.both ... as well as ...是错误的，绝对不可用。
7.下面各句里的both该去掉：
- The two boys are both alike.
- The two boys are both equally good.
- The two boys are both together.
