てもいい to ask if someone is allowed to do something


Can the てもいい form be used to ask if someone has the permission to do
something?

For example to ask if a women has the permission to smoke here :

> 彼女はここでタバコを吸ってもいいですか




# Short Answer

Yes, no problem.

* * *

# Variances

"Asking" includes several intentions. Verification, validation, confirmation,
and so on. Depending on such subtle nuance, you may want to insert an "ん" in
your example sentence.

Using the exact same English phrase for all the following scenarios may not be
the best choice, but I'll try sticking with _" Can/may that woman smoke
(cigarettes) here?"_ for each case. Note that they're all casual conversation
- not rude, not formal. Consider the likes of よい or 問題ない when looking for
formality.

## I'd say **彼女はここでタバコを吸ってもいいですか?** for:

### Yes or no question

You don't know the rules, don't really care about the general rules, and you
just want to ask if that woman is allowed to smoke, before she lights it up -
_Can/may that woman smoke (cigarettes) here?_

* * *

## I'd say **彼女はここでタバコを吸ってもいいんですか？** for:

### Wait! **Can** she?

The next day, you notice that woman is enjoying her smoke near a fire hazard
sign. Assuming she's violating the rules, you want to warn her so she don't
get in trouble. But before you act, you want to verify your assumption -
_Can/may that woman smoke (cigarettes) here?_

or

### What? Can **she**?

Inspired by her, you start smoking too. One day, you were told that you are
not allowed to smoke there. But nobody complains when **she** smokes. You
think it's unfair, and would like to challenge the situation - _Can/may that
woman smoke (cigarettes) here?_




Yes your sentence is correct, but it may be natural to use が here:

> 彼女がここでタバコを吸ってもいいですか？  
>  Is it okay if she smokes here?

This is because 彼女 belongs to a subordinate clause (ても-clause), where the
subject is not topicalized with は.

は is appropriate when a contrastive-は is intended or when "she" needs to be
emphasized as the topic of the entire sentence somehow. For example:

> 彼女はここでタバコを吸ってもいいですか？  
>  (Smoking is basically prohibited here but she may be special, so) can _she_
> smoke here?  
>  (Now let's talk about her next,) can she smoke here?

