Example 1:
1. I have lost my key. (I can¡¯t find it now.)
2. Bill has gone home. Or Bill went home. (He isn¡¯t here now.)
3. Have you had lunch? Or Did you have lunch?
4. The letter hasn¡¯t arrived yet. Or The letter didn¡¯t arrive yet.
5. She has gone to party. Or She went to party.
Example 2:
A) Do not use the present perfect with a finished time.
B) Use the simple past to ask : When¡¦..? or What time¡¦..?
1.I saw Ratana yesterday. (not I have seen)
2.Where were you on Sunday afternoon? (not Where have you been?)
3.We didn¡¯t take a vacation last year. (not We haven¡¯t taken)
4.When did they arrive? (not When they have arrived?)
5.Have you had lunch? Or Did you have lunch?
Example 3:
A) Present Perfect only (time until now)
B) Simple past only (finished time)
1.Have you ever been to Spain? (in your life until now.)
2.My friend is a writer. He has written many books.
3.We¡¯ve lived in Boston for six years (we live there until now.)
4.Did you go to Spain last year?
5.Shakespeare wrote many plays and poems.