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JLPT N4

〜てもいい

May / it's okay to...

Structure

Verb て-form + もいい

Used to ask for or give permission to do something.

Examples

  • ここに座ってもいいですか。

    ここにすわってもいいですか。

    Is it okay if I sit here?

  • 写真を撮ってもいいですよ。

    しゃしんをとってもいいですよ。

    It's fine if you take a photo.

  • 今日は仕事をしなくてもいいです。

    きょうはしごとをしなくてもいいです。

    You don't have to work today.

  • 昨日は早く帰ってもよかったです。

    きのうははやくかえってもよかったです。

    It was okay for me to go home early yesterday.

  • これ、食べてもいい？

    これ、たべてもいい？

    Is it okay if I eat this?

  • うん、使ってもいいよ。

    うん、つかってもいいよ。

    Yeah, you can use it.

  • 明日は来なくてもいいですか。

    あしたはこなくてもいいですか。

    Is it okay if I don't come tomorrow?

Common mistakes

  • Confusing てもいい (permission, may do) with なくてもいい (no obligation, don't have to) — they look similar but express very different things.
  • Attaching もいい directly to the dictionary form instead of the て-form (incorrect: 食べるもいい; correct: 食べてもいい).
  • Using a negated てもいい to answer 'no, you can't' — since てもいいです grants permission, a refusal should instead use だめです or いいえ、〜てはいけません, not a negated てもいい.

How it's different from similar grammar

  • てはいけない

    てはいけない expresses prohibition — something you are NOT allowed to do: ここでたばこを吸ってはいけません (You must not smoke here). てもいい expresses the opposite: permission — something you ARE allowed to do: ここでたばこを吸ってもいいです (You may smoke here). They are near-opposites in meaning.

  • なければならない

    なければならない expresses obligation (must do), while てもいい expresses optional permission (may do, not required). Its negative counterpart なくてもいい (don't have to) is the opposite of なければならない, not simply the negative of てもいい: 行かなくてもいいです (You don't have to go) contrasts with 行かなければなりません (You must go), while 行ってもいいです (You may go) is a separate idea about permission.

How this shows up on the JLPT

N4 listening and grammar sections often present short dialogues where someone asks 〜てもいいですか and test whether you understand the reply as permission granted or denied, and also test contrasting てもいい with てはいけない and なければならない in the same question set.

Quick check (3 questions)

  • 1. Choose the correct way to ask permission to open the window.

  • 2. Which sentence means 'You don't have to bring an umbrella'?

  • 3. A student asks「先生、辞書を使ってもいいですか。」and the teacher replies「はい、いいですよ。」What is the teacher granting?

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