N4 — outside your level filter
write + if + should have
kakeba yokatta
should have; wish I had — regret over what wasn't done
もっと早く寝ればよかった。
motto hayaku nereba yokatta.
I should have gone to bed earlier. casual
困ってたなら、言ってくれればよかったのに。
komatteta nara, itte kurereba yokatta noni.
If you were struggling, you could have just told me. casual