〜てもいい

Meaning

〜てもいい means it is okay to do something or you may do something. In question form, 〜てもいいですか means May I do this or Is it okay if I do this.

Formation

Use the て形 of a verb and add もいい. For a polite sentence, use 〜てもいいです. For a polite question, use 〜てもいいですか.

Usage

Use this pattern to say that an action is allowed, to ask if you may do something, or to check whether something is acceptable. It is common in classrooms, homes, shops, and public places.

Nuance

〜てもいい is softer than a command because it gives or asks for permission. The polite form 〜てもいいですか is very useful when speaking to teachers, staff, or people you do not know well.

Comparison

〜てください asks someone to do something. 〜てもいい allows someone to do something. 〜てはいけない is the opposite idea: it says something is not allowed.

Common Mistakes

A common mistake is forgetting も and saying 〜ていい in a situation where the standard beginner pattern 〜てもいい is expected. Another mistake is using 〜てもいいです when you actually want to ask permission; add か to make 〜てもいいですか.