表示因果: for, so, therefore, hence 　　從屬連詞 　　表示時間: when, while, as, after, before, since, until, as soon as, once 　　表示原因: because, as, since, now that, seeing that 　　表示條件: if, unless, in case, provided, suppose, as long as, on condition , 　　表示其他關系: though, than, as 　　My father, who had been on a visit to America, returned yesterday. 　　All the books, which had pictures in them, were sent to the little girl. 　　定語從句的引導詞 　　that, who, whom: 非限制性定語從句, 如果修飾人, 一般用who, 有時用that . 如果關系代詞在從句中作賓語, 就應當用賓格 whom 或that, 但在大多數情況下都可以省略掉, 在口語中可用who代替whom. 　　Here is the man youve been looking for. 　　He is a man you can safely depend on. 　　The people I spoke to is my cousin. 　　限制性定語從句如果修飾物, 用關系代詞that的時候較多, 也有時用which.. 當這個代詞在從句中是用作賓語時, 在絕大多數情況下都是省略的, 特別是口語中: 　　Have you everything you need? 　　anything I can do for you? 　　All you have to do is to press the button.