各种从句引导词总表一、如何使用宾语从句、主语从句、表语从句和同位语从句的引导词引导词作用例句That相对不缺少成分；陈述语气I knew that you were here just now.ifwhether相对不缺少成分；疑问语气从句的谓语动词为：ask;question;wonder-I doubt ifwhether he can do it well now. what缺少主语，宾语，定语（指物）1. You can be sure of what you have at present.2.I sold for what was enoughWho缺少主语，（指人）I wanted to know who will come.Whom缺少宾语，（指人）I dont know whom youre waiting for.When缺少时间状语He told me when we would gather.Where缺少地点状语
