employer可數(shù)嗎

　　To employ native English teachers to teach in China.

　　聘請母語為英語的教師來中國任教。

　　I'll engage in John's behavior if you decide to employ him.

　　如果你決定聘用約翰，我愿為他的行為擔保。

　　I'll engage for John's behaviour should you decide to employ him.

　　如果你決定聘用約翰，我愿為他的行為擔保。