I can't sleep. Does that mean I can't sleep or I can't sleep?

When we want to show that we can't or are not allowed to do something, we should use the word can't. Can't be in written form. Many people mistakenly write cannot as can not. American traditional dictionaries clearly point out that the negative form of can is cannot. Can't is used in spoken language, which is more casual, while can't is used in written language, which is more formal. But in any case, no matter how many people are using it, no matter how many domestic learning materials are recognized, when expressing the meaning of "can't or not allowed to do something", the writing of can not is wrong.

There are both meanings, and there can be no mistake here, so there is no mistake.