が苦手なんだ

am not good at

→ が

phrase Rare #27,211

am not good at 苦手 can also mean finding something difficult or feeling uncomfortable with it. なんだ gives the statement an explanatory tone; this form is casual.

JA: 私は人前で話すのが苦手なんだ。

EN: I'm not good at speaking in front of people.

トムは縦列駐車が苦手なんだよ。

Tom isn't good at parallel parking.

謝るのが苦手なんだ。

I'm not good at apologizing.

トムはトランプが苦手なんだよ。

Tom isn't good at playing cards.

子供の扱いが苦手なんだ。

I'm not good with children.

トムは自分のこと話すのが苦手なんだと思う。

I think Tom has a hard time talking about himself.

トムは数学が苦手なんだよ。

Tom is bad at math.

トムはフランス語が苦手なんだ。

Tom isn't very good at French.