The system says "Have you got his phone number?" is wrong. Well, is it? Seems acceptable to me.
It's great learning a foreign language - makes you remember reasons for learning/speaking the way you do in your native language. In British English, I was always told that "have you got" while valid, was poor English due to the redundancy of the word "got" - especially in written English. Having said that, you do hear it often enough.
Yep. A primary school teacher (in GB) insisted that you can always find a better verb than "got" and used to mark us down when using this verb. This worked well in a educational sense because when I'm trying to write something formal I naturally look for alternative. But to insist on the this in everyday English, as she did, is too extreme.
"Have you got..." should be accepted.
Why is "Do they have his telephone number?" wrong? Haben Sie can be used for [they have / you (formal) have] right? But I always manage to pick the translation that Duolingo doesn't like. Any help is appreciated.
The S in "Sie" is capitalised, indicting it's the formal form of "you": Haben Sie = Do you have..., Haben sie = do they have...
You normally know from the context whether someone means "do you have his number" or "do they have his number", but it can sometimes be confusing. This is a problem with DL as you encounter esch sentence out of context.
"Seine" means his. "do you have her phone number ?". would be "Haben Sie ihre Telefonnummer?"
well the correct translation in English is "do you have", instead of "have you", if you want so, you can say "have you got"
But the point of duolingo is to be able to help translate stuff, as well as understand the language - to understand a language means to understand meaning and concepts behind what's presented to you. If you were to translate stuff by "economy of typing" it'll make for some pretty poor reading when translated into english.
I'm not so sure - duolingo actually tends to accept economy of typing when it's logically and grammatically correct. So I type "2nd", or "kids", or "man" instead of "husband"; whatever works the quickest. With the translations it's a different game. You want pointless drudgery? Fine! But given it's so easy to make all correct answers valid, and that it's automated, I don't see why one size need necessarily fit all. Moreover, my original answer, "have you his number?" is perfectly acceptable English. Just as acceptable, I'd say, as "we have five elephants"!
In American English, we just tend to not say "Have you his phone number?" It is like saying "Run you to the store?" I would consider it very formal and British American-like (no offense to any, just what I hear from my British friends) to say it like that. It isn't normal syntax for American English.