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May / it's okay to
Definition
The grammar pattern 〜てもいい is used to express permission or to ask for permission. It is formed by attaching もいい (or polite form もいいです) to the te-form of a verb. This pattern is often used in polite or formal situations to show respect for the other person's opinion or decision. For example, when asking for permission to do something, the speaker is showing that they value the other person's opinion and are willing to follow their decision.
Structure
| Form | Pattern | Example |
|---|---|---|
| Te-form of the verb | Verb te-form + もいい | 窓を開けてもいい |
| Polite te-form of the verb | Verb te-form + もいいです | 窓を開けてもいいです |
| Te-form of the verb with です | Verb te-form + です + もいい | 窓を開けてもいいです |
Examples
すみません、ここに窓を開けてもいいですか?
Sumimasen, koko ni mado ga akete mo ii desu ka?
Excuse me, may I open the window here?
すみません (excuse me), ここに (here), 窓を開けて (open the window), もいい (may I), ですか (question particle)
先生、宿題は明日窓を開けてもいいですか?
Sensei, shukudai wa ashita mado ga akete mo ii desu ka?
Teacher, may I open the window tomorrow to do my homework?
先生 (teacher), 宿題 (homework), 明日 (tomorrow), 窓を開けて (open the window), もいい (may I), ですか (question particle)
ここに窓を開けてもいいです。
Koko ni mado ga akete mo ii desu.
It's okay to open the window here.
ここに (here), 窓を開けて (open the window), もいい (okay), です (polite ending)
Context
The grammar pattern 〜てもいい is used to express permission or to ask for permission in polite or formal situations. It is often used in situations where the speaker is asking for permission from someone in a position of authority or respect. In contrast, 〜てはいけない is used to express prohibition or to refuse permission.
Watch out
This is a common mistake because the two patterns are similar, but they have opposite meanings. To avoid this mistake, it's essential to understand the context and the speaker's intention.
This mistake can be avoided by paying close attention to the correct pattern and making sure to include the particle も between the te-form and いい.
This pattern is typically used in situations where the speaker is showing respect for the other person's opinion or decision. In informal situations, it's more common to use simpler patterns like 〜ていい or 〜ていいよ.
Strategy
When taking the JLPT, be sure to pay close attention to the context and the speaker's intention. If the speaker is asking for permission or expressing permission, look for the pattern 〜てもいい. Also, be careful not to confuse this pattern with 〜てはいけない, which expresses prohibition.
In context
Worked examples drawn from JLPT N5 test-style questions. Each sentence shows 〜てもいい used correctly, with a brief note on what the pattern is doing.
すみません、ここに座ってもいいですか。
Pattern used: 座ってもいいです
Adding か makes this a polite question asking for permission to sit. 〜てもいいですか is the standard way to ask 'May I...?'
A：「窓を開けてもいいですか。」B：「はい、開けてもいいですよ。」
Pattern used: 開けてもいいですよ
When granting permission, you echo the same 〜てもいい pattern. はい confirms the answer is positive — permission is given.
先生：「宿題は明日出してもいいです。」
Pattern used: 出してもいいです
The teacher is granting permission to submit homework tomorrow. 〜てもいいです conveys 'it's okay to do.' 〜てください would be an instruction.
Interactive
すみません、ここに______か。
Adaptive practice
Our adaptive engine will quiz you on this grammar pattern and track your progress toward mastery.