引導賓語從句的that之后接的從句不長時,可以省略.如果that后面的賓語從句較長時,that不能省略.
I hope (that) you'll be fine soon.我希望你盡快康復.
名詞從句中that,what用法比較：
引導名詞從句的that是連詞,在句中無成份,無意義,而what是連接代詞,what＝the
thing(s) that.
例如：It was told in yesterday´s newspaper that what the students had done was praised
by the factory.
連接代詞who,whom ,whose,what,which：它們起連接作用,作句子成分,各有其自己的意義.例如：
6）The teacher asked the new student which class he was in?（武漢市）（which引導賓語從句,在從句中作定語,修飾class,意為“哪個”.）
7）Can you tell me whom he is waiting for?（天津市）
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