Can you use the word not twice in same sentence?

You not only can use the word "not" twice in the same sentence, but you can even use it three times!

Here's an example:

"I am not not not happy."

This sentence uses "not" three times and is grammatically correct, although it's a bit confusing. It means the speaker is actually happy.

However, using "not" twice in a sentence is generally best avoided unless you are aiming for a specific effect, like emphasis or humor.