名詞從句的功能

名詞從句是由敘述句子或問句變化而成，和動名詞或不定式短語一樣，名詞從句也要被視為名詞。由於具有名詞的特性，故可做主語、謂語或be動詞之後的補語。

名詞從句做主語

例如：That honesty is the best policy is a proverb we should always keep in mind.

where he lives is still a doubt

whether he can do it remains to be seen

名詞從句做動詞的賓語

I know that he will go abroad in the nearest future.

I wonder whether he has finished the work.

I don't know how he'll handle it

名詞從句做介詞的賓語

用whether或疑問詞引導的名詞從句可做賓語，但that從句不可做介詞的賓語。

I am worried about whether he can do it

I am suspicious of how he'll cope with the problem

有時介詞之後也可以直接接that從句，形成慣用語

in that = because

except that 只可惜

for all that = with all that 儘管