How to remember using "have" instead of "of"? [closed]

I'm (reasonably) sure these are wrong:

• I would of won.
• I could of done that.

and are likely so common because if you phonetically transcribe "would've", "could've", etc, that's what you get. Nevertheless, I commonly make that mistake over and over again. How can I definitively correct this error?

Remove the modal verb (would, could, should, etc.) from the sentence, and see if it still makes sense.

• I would have won. -> I have won. (works!)
• *I would of won. -> I of won. (nope, that's not right...)

You can be sure that if the sentence is supposed to have have, then you can always remove the modal.

Well, "of" should never ordinarily come before a verb, or any part of a verb. If it does in one of your sentences, it should almost certainly be "have" instead.

The closest you legitimately get is something like "I'm tired of running"; I believe "running" there is what's called a gerund, that is to say a noun derived from a verb. But it's always "I should have run", never "should of". (In fact, "of" will never actually follow "would" or "should" in grammatical English, so that's another way you can check to see if you should replace it with "have".)