"I am still normal."
Translation:Tôi vẫn bình thường.
là is only used to equate a noun with another noun. Adjectives generally omit any verb so "I AM normal" is just "I normal" (tôi bình thường) whereas "I AM a singer" (tôi LÀ ca sĩ) requires là. Also là goes after vẫn in almost every case so "tôi vẫn là... " (I am still... insert noun).