掲示板 Forums - Can anyone tell me how this sentence is said in Japanese

My take on this:

"Look like a child" I would have rather translated as something along the lines of "子供のように見える"

"as smart as an adult" could be something like "大人と同じくらい賢い"

stringing those together with "may", could maybe in the end look like this: (私は) 子供のように見えるかもしれないが,大人と同じくらい賢い

Plugging that end result into Google translate it at least seems to convey the meaning you intended to get, but maybe someone else can vet fi what I stringed together here is natural Japanese and not just "technically correct" :)

My hubby is a fan, so I asked him. The phrase Conan uses in the manga/anime is 見た目は子供、頭脳は大人。literally: the appearance of a child, the brains of an adult.