純連詞就是在英語句子中起著連線從句的作用,本身沒有意義,也不在句中作任何成份。 that,if或者whether三個。例如:I said (that)I had been there before.(我說我以前去過那兒。) I wonder if (whether)she has received my letter.(我不知道她是不是收到了我的信。)