もっと慎重に

more carefully

→ もっと
phrase Rare #30,909
more carefully もっと means “more,” and 慎重に means “carefully” or “cautiously.” With なる, 慎重になる means “to become more cautious.”
JA: 次はもっと慎重に確認します。
EN: Next time, I'll check more carefully.

あなたはもっと慎重にそれをしなければならない

You need to be more careful when doing that.

もっと慎重になるべきだったね

You should have been more careful.

もっと慎重に言葉を選べ

Choose your words more carefully.

— 善き人のためのソナタ (2006)

次はもっと慎重にやります

I'll be more careful next time.

もっと慎重になることを学ぶべきなんだよ

You need to learn to be more careful.