employer可数吗

　　To employ native English teachers to teach in China.

　　聘请母语为英语的教师来中国任教。

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

　　如果你决定聘用约翰，我愿为他的行为担保。

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

　　如果你决定聘用约翰，我愿为他的行为担保。