"Where do they go?"

Translation: Où vont-ils ?

[Karl-A]

why is "où ils marchent?" wrong?

[Dermius]

Because that means 'where do they walk?' and not 'where do they go?'

[dudmdu]

And what is the difference?

[Karl-A]

"marcher - to walk" is by foot and "aller - to go" can also be any way to move, I suppose. Go by car or whatever.

[dudmdu]

Thanks! Now I see!

[KingRyan]

why not "Où ont-ils?"

[Hohenems]

As your sentence stands, it is wrong. It would translate as "where have they". If your sentence has a typo and you meant "vont", then it should be accepted.

[lacorbata]

I wrote "elles vont-où?" and it was accepted as correct. Would this be translated as "They go where?" and would it be considered weird to say?

[Shruti_x]

not in french! Statements such as that with a questioning intonation are acceptable when spoken and also when written but it's considered informal

[emw4124]

I wrote "Ou est-ce qu'ils sont allés?" Why is the past tense wrong?