要看which在定语从句中作主语还是作宾语.如果which在定语从句中作主语,后面就该是谓语动词；如果which在定语从句中作宾语,后面就该是主谓结构后,主语可能是名词,也可能是代词.如：
1.Years ago,I bought the book which helps me much in learning English.(which后接谓语动词helps)
2.The book which he lent me is for the way of learning English.(which后跟的是作主语的代词he)