References:
https://www.youtube.com/watch?v=Te-r-GF2c1U
https://www.zhihu.com/question/34050582
Tense: percent perfect
Status: stative (result)
Example:
I haven’t eaten snail.
The Chinese mothers have always been manual labourers, whereas the daughters have had the opportunity to educate themselves and climb the social ladder.
Tense: present perfect continuous
Status: dynamic (duration)
Example:
I have been learning English since I was a boy.
Tom has been playing football for 2 hours.
Tense: past perfect
Status: stative (result)
Example:
I found out that he hadn’t met him before.
Tense: past perfect continuous
Status: dynamic (duration)
Example:
He told me that he had been waiting for 20 minutes.