Why is this "Heb je honger?" and not "Hebt je honger?"?
You drop the -t ending when the verb comes before the second person pronoun. Examples: Jij hebt honger = You are hungry. Heb jij honger? = Are you hungry? Je draagt een hoed = You wear a hat. Draag je een hoed? = Do you wear a hat?
One other detail: does the same happen with "u"? "Hebt u honger?" or "Heb u honger?"?
Only with je/jij, not with u.
To be very correct, when je/jij comes after the verb, the ik conjugation is used. Usually this means the -t is dropped, but not always, e.g.:
Very clear; thanks!
Is word order important here like it is in English? I.e. "heb je honger?" Means "are you hungry?". While "je heb honger" can only be the statement "you are hungry".
Yes, it's the same in Dutch.
Is U short for Jullie?
Why the plural translation is not accepted? Hebben zij honger?
Hebben zij honger? = Are they hungry?
Plural you = jullie
And "Hebben u honger" is also wrong? So its "hebben jullie honger" in plural right?
Yes. U would be Heeft u or Hebt u.
Why is it telling me im wrong and i have to use "u" instead of "je"? How do i know which one's right?
You can use:
I answered it wirh the plural "jullie hebben honger?" And it rejected it, was i wrong or should i flag this question?
The wordorder for questions = Verb - subject - rest
Which is accepted.