Sono sorpreso dal fatto che tu sia così infantile.

[sindaco]

English Translation

I’m surprised that you’re so naïve.

In the vast majority of sentences on Tatoeba, “naive” seems to correspond to “ingenuo”, and “infantile” seems to correspond to “childish”.

Also, I just noticed that the i in naive in the English sentence here has the Umlaut-type accent on it (naïve), which is generally used in languages like Dutch for example, but which I’ve never come across in English.

[Floria7]

@sindaco, with you all the way here. Infantile - childish etc etc.

[pitti42]

Using a diaresis in “naïve” is not uncommon in english. I’ve seen it pretty often. It’s just that most natives probably don’t have the keys on their keyboard to type it, and just write it without.