Hi,
I think the modal verb 'would' can be used in two ways: one as a past tense of 'will' and the other as a word to ask somewhat politely -- make a request, that is.
Now, my confusion is how do we know when one meaning is being employed and not the other? Do we anticipate any possible confusion arising in any sentential situation due to its dual functionality (note: I don't know the underlined is a correct one to use for the sentence.)?
1) John said "he will carry the bag for me."
John said he wourld carry the bag for me.
2) Can you carry the bag?
Would you carry the bag?