both的词性有两种，分别是副词和代词。both用作形容词与定冠词、指示代词、形容词性物主代词、名词所有格等限定词连用时，应置于其前，而不能置于其后。both用作代词时可作主语、宾语和同位语。常见句型。There are trees on both sides of the street.这条街两侧都是树。Both these flowers are beautiful.这两朵花都好看。Both my parents are kind.我的父母都很亲切。I don&#39t like both of them.他们俩我不是都喜欢。We both participated in this work.我们俩都参加过这一工作。