How can I know when I should use can, could and would?

Respostas

Use "can" if you intend to do something, or if something is possible.
eg.

Question:"You can't lift this much weight, can you?"
Answer:"Sure I can!"

Use "could" if you want to say you can but you don't intend to do it.

Question: "You can't lift this much weight, can you?"
Answer: "I could if I went to the gym more!"

Use "would" if you want to say you can and you intend to, but something is preventing you.

Question: ""You can't lift this much weight, can you?"
Answer: "I would, but I hurt my back yesterday."

When you're asking the question, the usage can become irrelevant depending on the options available to the person being asked:

Question: "Could you chop these onions for me?"
Question: "Can you chop these onions for me?"
Question: "Would you chop these onions for me?

No matter what is asked, I understand that they want the onions chopped now.

However when asking a question without something being obvious, using the right word does have a different meaning:

Question: "Can you kiss Stacey" (Kiss Stacey please)
Question: "Could you kiss Stacey?" (Kiss Stacey please (less immeditate/Is it possible?)
Question: "Would you kiss Stacey?" (Do you like Stacey? Would you ever kiss her?)

I hope this helps. They are such similar words that the rules for them are not so strict. The best thing to do is pay close attention to the intonation (way they are said), that will be the key. :)

Highly-rated answerer

@tomuchan oh thank you!! This really helps :)

Highly-rated answerer

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