When using 'do-support' the verb that follows 'do' (or its inflections) is always the bare infinitive which does not inflect, e.g:
- Does your computer work? (NOT: does your computer works?)
- Did she walk home? (NOT: did she walks home?)
- Does the aparment have a balcony? (NOT: does the aparment has a balcony?)
Of course you could also pose the question like so:
- Has the apartment a balcony?
Then you would use 'has', but only in British English and not in American English, at least according to this article:
British English: He has a car; Has he a car? American English: He has a car; Does he have a car?
My primary teacher taught us the "helping verb" + "main verb" rule.
She works = She does work She worked = She did work She has worked = She has worked He does = He does do (confusing right) They work = They do work We have = We do have
Now, to form a question, just change the position of the helping verb and the subject:
She works -> She does work -> Does she work? She has worked -> Has she worked? We have -> We do have -> Do we have?
Masculine nouns in the accusative case use "einen," and the verb "haben" puts "Balkon" in the accusative case.
In Australia, it is more common to say you live in a unit, not apartment or flat. My sentence was marked incorrect because I used the word unit, but the sentence structure was correct. Perhaps this word needs to be added to the default answers for the Aussies learning on here.
Kindly correct the UK version.
There is no "UK version".
Duolingo uses American English to teach you German.
UK English words are usually accepted (e.g. you could enter "Does the flat have a balcony?"), but the default translation will (almost) always be an American one.