What's the most appropriate way to stop someone on the street and ask if they speak English?

Question

I learned I can do it in following ways:

1. ¿Disculpe, hablas tú inglés?
2. ¿Disculpe, tú hablas inglés?
3. ¿Disculpe, habla usted inglés?
4. ¿Disculpe, usted habla inglés?
5. ¿Disculpe, hablas inglés?
6. ¿Disculpe, habla inglés?

Questions:

a. Is there any difference what order "habla" and "usted" are in (1 vs 2 and 3 vs 4)?

b. Is it more appropriate to include the pronoun usted/tú or can it be omitted (5/6 vs 1/2/3/4)?

c. Would it be appropriate to use informal tú if talking to someone younger than me (1/2/5 vs 3/4/6)?

Answer 1

There's a lot of sociolinguistic issues going on between tú vs Vd. If someone is younger than you, you can generally use tú, but the details are best left to one of the questions on here more directly suited to it, but when in doubt, use Vd..

Omiting the pronoun can always (and, preferentially) be done with tú. With Vd. it is better to include since you haven't previously established whom the third-person conjugation refers to.

As to the order of the pronouns, there is actually a difference in meaning. When you ask ¿Habla usted inglés?, you are genuinely curious as to whether they speak or not (it's a true interrogative statement). When you ask ¿Usted habla inglés?, you're actually taking a declarative statement, and turning it into a question (cf. "You speak English?"), which makes is what makes it sound a bit rude, since it presupposed that they do and you're questioning that presupposition, or the exact opposite — that you're surprised that they do, and questioning it.

Answer 2

Since you are addressing someone you don't know I would use "usted", except if you are addressing to someone much younger than you or if depending on the context may seem inappropriate to be too serious or too formal.

To me, #3 is the one that sounds best (along with #5). Note that #1, #2 and #5 should be

¿Disculpa (o perdona), hablas inglés?

and not Disculpe.

Also, #2 sounds a little bit rude to me, like if it had some tone of skepticism.

So I would go with:

¿Disculpa, hablas inglés? / ¿Disculpe, habla usted inglés?

Answer 3

In Spanish we don't need to emphasize or clarify the subject as in English or French, the conjugation tell us clearly. So, from your 6 choices in the first 4 you can avoid to say the pronoun. Guifa explais it very well.

Now, about your options: The 1 and 2 are incorrect for me, in the way that don't sound natural. Not for a native speaker. And if you want to be not so formal and use tú then you should use in concordance Disculpa and not Disculpe. The same mistake is in the number 6.

The 3 and 4 are in the same case. But for me, between 3 and 4, 3 sounds better.

Definitively the 5 is the best one. But you should write:

Disculpa, ¿hablas inglés?

When to use tú and when usted is a little bit difficult. In my case, if I talk with a young person or with someone younger than me I'll use tú the most of times. But if is someone older than me automatically I use usted. That could be an empirical rule you can use. Perhaps I'm not so polite because I rarely use explicitly the pronoun usted when I ask something to someone in the street.

A curious fact: in my country, or at least where I live, if you want to know if a native Spanish speaker speaks English just ask him/her in English, if he or she understand you and knows how to answer then you can know it.