なんじゃないかな

I think ...; maybe ...

→ だ
phrase Rare #30,250
I think ...; maybe ... Adds a tentative, conversational tone to a guess or opinion, like “I wonder if ...”
JA: 明日は雨なんじゃないかな。
EN: I think it might rain tomorrow.

そんなに心配しなくても大丈夫なんじゃないかな。

You probably don't need to worry that much.

トムが言ったことは嘘なんじゃないかな。

I think what Tom said might have been a lie.

トムのお父さんは弁護士なんじゃないかな。

I think Tom's father might be a lawyer.