I know this is correct "My big brother is twice as big as me"
Can I say "My big brother is twice as big than me"?
English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It only takes a minute to sign up.Sign up to join this community
You’ll be understood, but your first example is more grammatical.
Also, you should use the subjective pronoun “I” instead of objective pronoun “me” because you wouldn’t say ”me am.”
Therefore, the sentence, “My big brother is twice as big as I am,” would be what you want to use. Although, it does sound a bit awkward, and perhaps rephrasing it would thus be your best option.