When it comes to absolute adjectives, either it is or it isn’t.
You’ve probably heard statements like ‘That’s a fairly unique design’ or ‘He has a very unique style’. The problem is that ‘unique’ is what we call an absolute adjective. Something is either unique (the only one of its kind) or it isn’t; there are no degrees of uniqueness.
Just one of the brilliant things about a shared language is that it brings clarity of meaning. Whenever we communicate, we should at least try to avoid ambiguity and confusion. A discussion about whether to use ‘may’ or ‘might’ illustrates this point really well.
I’ll start with a couple of statements. They are not hard and fast rules but, if you follow them most of the time, you won’t go far wrong.