よく知ってるよ

I know ... well

→ 良く
phrase Rare #25,017
I know ... well Casual way to say you know someone or something well; the subject and object are usually understood from context.
JA: この辺の道はよく知ってるよ。
EN: I know the roads around here well.

お兄さんのこと、よく知ってるよ。

I know your older brother pretty well.

この歌はよく知ってるよ。

I know this song well.

彼はあの街のことよく知ってるよ。

He knows that city well.

彼女のことなら、よく知ってるよ。

I know her very well.