が怖いんだよ

… is scary

→ が

phrase Rare #30,304

… is scary The thing before が is what someone is afraid of; the person who feels afraid is often understood from context. んだよ adds an explanatory, emphatic tone.

JA: 高いところが怖いんだよ。

EN: I’m afraid of heights.

みんなトムのことが怖いんだよ。

Everyone is afraid of Tom.

俺、お前の父ちゃんが怖いんだよ。

I'm scared of your dad.

お母さんが怖いんだよ。

My mom scares me.

マジでクモが怖いんだよ。

I'm seriously afraid of spiders.

コウモリが怖いんだよ。

I'm scared of bats.

彼はとても母親が怖いんだよ。

He's really afraid of his mother.