I bought two expensive dictionaries here half an hour ago, but I forgot to take them with me.
Who served you, sir?
The lady who is standing behind the counter.
Which books did you buy?
The books which are on the counter.
Did you serve this gentleman half an hour ago, Karen? He says he's the man who bought these books.
I can't remember. The man whom I served was wearing a hat.
Have you got a hat, sir?
Yes, I have.
Would you put it on, please?
All right.
Is this the man that you served, Karen?