by改成什么了

by不能改成什么，它做介词和副词用。

例如by加交通工具，表示乘什么，by boat，by subway，by train等。

例句：They went to school by train yesterday afternoon.

还有短语by the way，by here，by somebody.

例句：By the way，Where is Jenny Brown?

例句：Chinese is spoken by many people.