我想問1問verb to be系乜?同有乜時候系用could?

verb to be




I
am
a student.

He
is
a teacher.

She
is
a journalist.

It
is
a book.

We
are
mechanics.

You
are
pilots.

They
are
policemen.

"Could" is used to express possibility( 表達有可能性)or past ability as well as to make suggestions( 建議)and requests(要求). "Could" is also commonly used in conditional sentences as the conditional form of "can."
example:
Extreme rain could cause the river to flood the city.(possibility)
Nancy could ski like a pro by the age of 11.(past ability)
You could see a movie or go out to dinner.(suggestion)
Could I use your computer to email my boss?(request)
We could go on the trip if I didn't have to work this weekend.(conditional)
could 亦係 can 架 past tense! 所以could之後唔需要+ed.
+ed係simple past tense.
example:
I lived in United State for two years.(is already past)
We talked on the phone for an hour.
有d情況(simple past tense)唔需要+ed
He sat at the beach all day.(sit--->sat)
I saw a movie yesterday.(see---->saw)

I hope this can help you!