本当にゴメンよ。

本当にごめんよ。

I'm very sorry.

本当(ほんとう)にゴメンよ。

Hontōni gomen yo.

本当に (ほんとうに、ほんとに、ホントに、ホントーに、ホントウに)

really; truly

御免 (ごめん)

your pardon; declining (something); dismissal; permission

よ (よ)

indicates certainty, emphasis, contempt, request, etc.; used when calling out to someone; used to catch one's breath or get someone's attention; yo!

Readings: ホン、もと

Meanings: book, present, main, origin, true, real, counter for long cylindrical things

Readings: トウ、あ.たる、あ.たり、あ.てる、あ.て、まさ.に、まさ.にべし

Meanings: hit, right, appropriate, himself