Monsters speak ungrammatically

[curiousmarcus]

Cookie Monster: Me want cookies.

Child: Me want cookies? Why does he speak that way?

Parent: Because he's a monster that's why. Monster speak ungrammatically.

I feel that native speakers won't put it that way. What's a more natural way of saying it?

Also, what do you call a word that is in the format of un-something? An adjective that isn't really a new word by itself but simply negates another word? Given that, I think I'm looking for a word that means ungrammatical but is not in the un-something format.

 

[GoesStation]

You can say he speaks broken English, but ungrammatically works well, too.

 

[emsr2d2]

To a child, I might say something like "Because monsters sometimes get things wrong" or "Because some monsters talk in baby English".

(Of course, the teacher in me would be shouting at the television "For crying out loud, it's "I want cookies"! Stop teaching kids ungrammatical English!")

 

[Raymott]

They are often colloquially referred to as "un words" if a Google search is anything to go by.
Prefixes meaning the same are in- and ir-.
invisible, inattentive, incapable.
irregular, irresponsible, irrational.

 

[Skrej]

(Of course, the teacher in me would be shouting at the television "For crying out loud, it's "I want cookies"! Stop teaching kids ungrammatical English!")

Ironically, Sesame Street is of course an educational program for children, although it focuses on the alphabet, numbers, and colors, rather than grammar. However, it does introduce some basic vocabulary.