A which和who用于指物的例子：
What will you have to drink?
你想喝点什么?
There is gin，whisky and sherry;which will you have?
我们这里有杜松子酒、威士忌酒以及雪利酒。您想要哪一种?
What does it cost to get to Scotland?
It depends on how you go.
Which(way) is the cheapest?/Which is the cheapest(way)?
到苏格兰去要花多少钱?
这要看你怎么走。
哪一种走法最省钱?
Ive seen the play and the film.
What did you think of them? Which(of them) did you like best?
我看了戏剧和电影。
你觉得(它们)怎么样?你最喜欢哪一个?
B which和who用于指人的例子：
Who do you want to speak to?
I want to speak to Mr Smith.
We have two Smiths here. Which(of them) do you want?
你想找谁谈?
我想找史密斯先生谈。
我们这里有两位姓史密斯的。你要找的是哪一位?
which(代词)指人的时候，不能单独用做动词的主语：
Which of you knows the formula?
你们谁知道这个公式?(of you是必要的。)
也可以说：
Who knows the formula?
C which(形容词)表示轻微限定的意思时可以用于指人：
Which poet(of all the poets) do you like best?
(在所有的诗人当中)你最喜欢哪一位诗人?
这里可以用what代替which，并且更合乎逻辑，但通常避免用
形容词what来指人。