～てもいい
permission to do
～てもいい expresses permission. It is made by taking the て-form of a verb and adding もいい, literally “even if (you) do it, it is good”.
For English speakers, it works like “may” or “it is okay to ...”. With ですか at the end it asks for permission. Without the question it gives permission.
1. Asking for permission
Add ですか to ask politely whether you may do something.
ここに座ってもいいですか。
“May I sit here?”
- ここ = here
- に = place marker (where the action happens)
- 座ってもいいですか（すわってもいいですか）= may (I) sit?
2. Giving permission
The same pattern without a question gives the listener permission. Adding よ at the end makes it sound friendly and reassuring.
窓を開けてもいいですよ。
“You may open the window.”
- 窓（まど）= window
- を = object marker
- 開けてもいいですよ（あけてもいいですよ）= it is okay to open (it)
How to form it
Verb て-form + もいい
- 座る（すわる）= to sit → 座ってもいい（すわってもいい）= may sit
- 食べる（たべる）= to eat → 食べてもいい（たべてもいい）= may eat
- 帰る（かえる）= to go home → 帰ってもいい（かえってもいい）= may go home
Key idea
～てもいい literally says “even if you do it, it is good”. Whenever you want to ask for or give permission, this is the pattern to use.
Built on the same stem
Updated .