อ่านเรื่อง Second Conditional IF มันจะบอกว่า

If + Simple Past Tense + Would / Could / Should / Might + Verb

เช่น If I were you, I wouldn't drive so fast.

แต่อ่านเจอเนื้อเพลง ของ You+Me - Break the Cycle เนื้อเพลงตอนนึงเขียนว่า

if you were mine, I would've looked into those eyes and said...

เลยไปอ่านเจออีกอันนึงคือ

Must Have / Would Have

Referring to past events. Must have + V3 is when we talk about our strong opinions based on evidences / facts.

- Do you know Ryan's math grade?
- I don't know but he must have got an A. (His math is really good)


Would have + V3 also refers to past events. Similar to could have and might have but would have is more about something we chose to do or not to do in the past because a certain necessity was not met. Something was missing and that we chose to do what we did and that would have is usually combined with if clauses.


I would have moved out but I hadn't had enough money.
(I wanted to move out but I didn't have money)

I would have been smiling if you had brought me some flowers.
(You didn't bring me flowers, so I am not smiling)

I would have never divorced him if he hadn't hit me.
(I would never divorce him unless he hit me. / He hit me, I divorced him)

ที่มา http://www.grammarbank.com/could-should-would-must-have.html

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