I Would if I Could . . .

Some people might consider the distinction between could and would to be only a matter of degree of politeness (would being more polite than could). But could encompasses additional meanings and connotations.

Could is the past tense of can (to be able to do, make, or accomplish), but it also refers to an ability or possibility in the past.

• When I was younger, I could run a mile without getting winded.
• Before cell phones, you could actually engage family members in face-to-face conversation.

Could also implies possibility but in a slightly different sense than can. The statement, “We can hold five adults in our car” shows capacity. There is room for five. Using could instead gives it a slightly different meaning. It’s likely to be true or happen. It’s possible that five people will need a ride.

Could is also used to refer to something that you wish to have or do but that is not possible. (If I could win the lottery, we’d be out of debt!) Could have describes something that was possible but didn’t happen. (We could have won the lottery if we had bought a ticket.)

Would has fewer, more specific uses. Use would for unreal or unlikely situations. (I would quit my job if I had a million dollars.” Would have describes a situation that could have happened but didn’t. (I would have been home earlier if I’d known it was an emergency.)

And, of course, use would to ask polite questions or to wish for something:

• Would you mind if I quit talking about this subject?
• I wish you would quit talking about this.

Wish granted.