Błędnie: I don't think you should put on these trousers. They don't really suit your sweeter. Poprawnie: I don't think you should put on these trousers. They don't really suit your sweater.
"Sweeter" to stopień wyższy przymiotnika "sweet" ('słodki'). "Sweater" to 'sweter'. Inaczej na 'sweter' można także powiedziec "jumper" (bryt.), a na rozpinany "'cardigan"