I asked a few native speakers about which phrase was more natural in a situation where I ask a friend if they had time:
時間がありますか?
or
時間はありますか?
They all chose the latter. So is the former unnatural? In what situations would you use it in?
I asked a few native speakers about which phrase was more natural in a situation where I ask a friend if they had time:
時間がありますか?
or
時間はありますか?
They all chose the latter. So is the former unnatural? In what situations would you use it in?
I'm amused to read all of your native Japanese speaking friends chose 時間はあります. To me 時間があります and 時間はあります sound the same, and look interchangeable as a postpositional particle - は、が following the subject..
If I was asked which of が and は I would choose in the following examples, I would choose
バッテリーの交換は30分かかります。(お待ちいただく)時間はありますか?
開宴まで5分です。トイレに行く時間はありますか?
もう60歳だ。残された時間はない
まだ十分考える時間がある
くだくだ言っている時間はない
But it doesn’t mean the other option would be grammatically wrong.
Frankly I don’t know why I chose them this way. It might be just intuitive for me, and it is a matter of taste at best. I don’t think the choice of は and が makes any significant difference in meaning or grammaticality in most cases.
As a native speaker, I would also definitely choose your second sentence using 「は」 if you just asked me:
"Which phrase is more natural in a situation where I ask a friend if they had time?"
without giving any more specific information. In other words, the exact context. What is the situation in which you are asking this friend if s/he has time? What exactly did you and/or s/he say immediately before you uttered the sentence 「時間( )ありますか?」, etc.?
Japanese is an extremely contextual language; Context is king. And believe me, that is still an understatement.
With over three decades of experience with Japanese-learners, I know well that their "favorite" subject marker is 「が」 for the reasons I have yet to understand to be honest. Many use it as if it were the default option.
You need a good reason to use 「が」 over 「は」, but the question "Do you have time?" is so generic in nature that choosing to use 「が」 is not only fairly unnatural but is also highly unjustifiable.
It's not technically impossible to use 時間が… for questions (unlike sentences of statement that represent speaker's judgement) but it may sound like you suspect that they have time. Usually, you use a sentence that contains some topic when you ask people and expect them to reply, for them to follow the topic you have staked.
One option that might be overlooked is to omit the particle, as opposed to choosing "は" or "が". In this case, it would sound much closer to "は" than "が".
Personally, I would go with this third option, in most cases.
Nonetheless, I concur that context really is important when discussing Japanese. There are cases when one would sound correct, and the other incorrect and vice versa.
In what situations would you use [the former] in?
When the subject is made clear to be someone other than the listener.