My mother is a teacher----English.(of,in,for,on)

of
His training qualifies him as a teacher of English .
他受的训练使他有资格做一个英文教师.
He substitutes as our teacher of English.
他代任我们的英语教师.
请及时采纳,不懂继续问
再问： 为什么 ( ⊙o⊙?)不懂