復數。both... and...連接兩個并列成分（名詞，代詞等）。作主語時謂語動詞用復數。例句：Both you and he are students.你和他都是學生。Both Jim and Lily are happy.吉姆和李莉都很開心。

both的用法

both用于系動詞、情態動詞和助動詞之后，實義動詞之前。

如；

1、We are both students.

=Both of us students .

2、We both like English.

=Both of us like English.

both相關例句

The data is limited in terms of both quality and quantity.

這份資料在質量和數量上都很有限。

They were both only 20 years of age.

他們兩人都只有20歲。

They both had some right on their side.

他們雙方都有一定的道理。