"Fine with/by/to you/that"

Are there any differences when asking the following?

1. Would that be fine with you?

2. Would that be fine by you?

3. Would that be fine to you?

What if we switch you and that around? Do they still make sense?

1. Would you be fine with that?

2. Would you be fine by that?

3. Would you be fine to that?

This is somewhat idiosyncratic, as the specific choice of preposition depends on the adjective that you use preceding. However, with both of the examples that you've given, my judgements are the same:

With is preferred:

Would that be fine with you?

Would you be fine with that?

By is acceptable in the first form, but marginal in the second:

Would that be fine by you?

? Would you be fine by that?

And to is wrong in both forms.

Would that be fine with you?

Makes sense and means what you probably want it to mean. Stick to it!

Would that be fine by you?

This is used quite often, but I think it sounds more informal. If you can avoid it, do so!

Would that be fine to you?

I don't think I've ever seen/heard/read this used, so unless I'm not imagining a situation where it would be suitable, I'd say it's ungrammatical.

Would you be fine with that?

Expresses the same thing the first question in my answer does. You can happily use it.

Would you be fine by that?

This reminds me of, for example, "would you be fine by tomorrow morning?" meaning, "will your condition still be fine when tomorrow morning arrives?" But I have no idea what could "by that" express, I'm pretty sure it works only with "by then". Therefore, the original question is probably ungrammatical.

Would you be fine to that?

Also sounds wrong and unsuitable for any situation. Avoid it!

Let me think about this. This is a question of usage. My instinct says ...

I would NEVER say #3 "fine to you".

I might say #2 "fine by you" as to say: « in my opinion ».

I would say "fine with you" if it was with me personally. #1 seems to be a personal thing. #2 seems to be an opinion thing.

I could substitute #2 with "That be fine according to me." or "That be fine in my opinion."

I could substitute #1 by saying "That would be fine with me personally."

    1. Would that be fine with you?

    2. Would that be fine by you?

    3. ___Would that be fine to you?___

As for the second choice, I would never say #3. I'm still deciding if I like #2.

    1. Would you be fine with that?

    2. **Would you be fine by that?**

    3. ___Would you be fine to that?___

Usage is very ticklish, and full of nuance. I had a very British education, outside the UK. When I first visited England, I found myself able to adapt quickly to UK English. But when I went north to Scotland, I lost all my references: it was like going back in time 300 years. Preposition usage especially was completely different in Scotland. When you go to McDonald's there, you "take away" your burger ("take out" in Canada). "Take Away" in my dialect means I'm confiscating the burger! :)

I'm an English teacher, living in French Quebec, originally from Newfoundland, living in central Canada. My personal dialect is eclectic.

As others have said, to is probably never a good choice.

I expect many people will say the choice between with and by in (1a) and (2a) is an arbitrary matter of style. But I feel by implies there are other people who also need to be consulted rather than just you, whereas with carries no such implication one way or the other.

I wouldn't want to make too much of it, but I personally don't really like the word fine at all in the second set of sentences. I'd use happy, okay, content, or similar. My problem is the way fine switches from modifying "that", to modifying "you". I can just about tolerate (1b), but I'm afraid Would you be fine by that? sounds just awful to me.