Of/Have
This is one I’ve started seeing used incorrectly fairly often in print. Confusion around the use of these two in phrases such as ’should have,’ ‘would have,’ ‘could have,’ no doubt arises from the contracted forms:
should’ve
would’ve
could’ve
Now I see in print “I should of” or “We could of” when no doubt the writer meant “I should’ve” or “We could’ve.” They sound the same when you say them, but they are completely different. “Of” is a preposition (I know, we’re getting technical), whereas ‘have’ is one of the three helping verbs: have, be, and do.
Let’s just try substituting one for the other in a less ambiguous context. For instance: You wouldn’t say “We of been here for an hour.” You would say “We have been here.” Similarly, you couldn’t say “She thought have him,” but you would say “she thought of him.” Hopefully this shows that they’re not interchangeable.
Lose/Loose
Under most circumstances, one is a verb, the other is an adjective. “Lose” is the verb. You can lose your keys, lose your mind, lose your lunch. If you lose something, it’s lost. Until it’s found.
Loose is, most often, an adjective. Loose rhymes with goose. You can have a screw loose, in which case you might lose it. If you lose weight your clothes will feel loose (how nice).
There are other uses for each word that you can look up in any dictionary of your choosing, but these are the most common situations where these two get mixed up.


