1.Has he met Mrs.Jones yet?
Yes,he has already met Mrs.Jones.
When did he meet Mrs.Jones?
He met Mrs.Jones two weeks ago.
2.Has the boss left yet?
yes,the boss has already left.
When did the boss leave?
The boss left ten minutes ago.
你看,题目是1/2/3的格式
回答是Have/Has(看1的人称）+1+2（动词过去分词形式）+yet?
Yes,1+ Have/Has(看1的人称）+already+2（动词过去分词形式）.
When did +1+2（动词过去式形式）?
1+2（动词过去式形式）+3.