I have a simple question of English. This is correct?
The type "red" doesn't exist.
Or "not" or "don't"? And why?
The type "red" ______ exist.
- doesn't
- not
- don't
I know what "does" is use if the person is "he, she, it".
Doesn't is simply a contraction of does not. They are interchangeable, with does not preferred in written language and doesn't in spoken language. In terms of meaning, they are 100% equivalent.
Don't is a contraction of do not. This can be used as an instruction to a person "Don't do that!" / "Do not do that!" or when referring to plural things "Male bees don't have a sting" / "Male bees do not have a sting".
In your example the colour red is an 'it' so the correct answer is 'The type Red doesn't (or does not) exist'.