I have some English grammer question?

Would have done - 本來將會做﹐但是結果無做到
Could have done - 本來可以做﹐但是結果無做到

兩個都是指件事並無做成(或無發生到)。句子是用緊active voice 同埋past tense。成個句子的subject 是人。例如﹕
I would have gone to see the doctor if I didn’t have to go to work.
What would he have done if he had $1M?


Will be done - 將會被完成
Can be done - 可以被完成

句子是用緊passive voice 同埋future tense。成個句子的subject 是事。例如﹕
The project will be finished on time (by us).
The problem can be solved in a peaceful way.

WILL is used to express:
Request
Offer
Promise
Threat
Warning
--------------------------------
WOULD is used in the INTERROGATIVE to express
Polite offer
Polite request
--------------------------------
CAN is used to express:
Ability
Request
Offer
Possiblity
Permission
-----------------------------
COULD is used to express:
Ability in the past
Polite request
Possibility
Permission
------------------------------

WILL 同 would
是指意願上會否做(willingness)

can 同 could
是指能力上能否做(ability)

would have done = 會做好
could have done = 能夠做好

will be done = 將會被完成
can be done = 能夠完成