假如我们说〝我不知道他住在哪里〞，或者〝他究竟住在哪里仍是个谜〞，我们就可以用这种问题型式的名词子句，每一个名词子句都要用who, where, whether, which等来开始。以下是典型的例子： 

i don't know where he came from.（我不知道他来自何处。） 

whether or not he is an american is still a secret.（他是否是个美国人仍然是个秘密。） 

i will find out where he is living.（我要找出他住在哪里。） 

i can not remember whether he smokes or not.（我不记得他是否吸烟。） 

please let me know how old he is.（请让我知道他多大年纪。） 

kindly tell me what you really need.（请让我知道你需要什么。） 

you have to decide which book you want to buy.（你应该决定买哪一本书。） 

do you know where he is from?（你知道他是从哪里来的？） 

do you know who he is?（你知道他是谁吗？） 

please ask your brother whether he is coming or not.（请问你的兄弟他会不会来。） 

when she is coming remains a puzzle.（她何时来仍然是个谜。） 

i don't know what he is interested in.（我不知道他的兴趣何在。） 

i don't understand what he is talking about.（我不知道他在谈什么。） 

do you know whose bicycle this is?（你知道这辆脚踏车是谁的吗？） 

do you know which country hawaii belongs to?（你知道夏威夷属于哪一个国家吗？） 

you should ask your mother where you were born.（你应该问你的母亲你在哪里生的。）