Quick english question

[The Don]

I don't know where else to post this but if someone said "That is my most best thing in the world" what type of mistake would that be, like whats the name of it. I don't know if you will understand what i am on about :rolleyes:

[N!ck]

I'd just call it horrible grammar.

Favourite is the word to replace it with.

[Geraint]

"That is the best thing in the world to me"

No need for the most as the word best would suggest nothing is better.

[FlyingJesus]

I'd call it bad syntax, I suppose you could label it as a grammatical error but that isn't really what it is.