我想問幾時應該用Present Perfect 幾時應該用Past Perfect呀?

1. 幾時應該用Present Perfect :
~剛剛做完就用Present Perfect ,如 I have already eaten an apple. She has already done her homework.
~已做了一段時間,現在仍在做,如: I have lived in Hong Kong for ten years. He has lived in Kowloon since 2002.

記着: 1. have/has + past participle(p.p) ; he, she ,it 要用has.
2. just, already, yet, for, since 是提示字眼


2. 幾時應該用Past Perfect呀?
~有兩個過去嘅動作,要清楚表達出它們發生的先後次序,如:
Yesterday, I had cleaned my teeth and went to school.
She dressed it before she had paid for it.
He ate the bread after he had cut it.

記 着: had +p.p., 一定要分析哪一個動作發生先

一定要熟動詞表;
past participle:

eaten, drunk, gone, done, taken, drawn .......