"Stängde du dörren?"

Translation: Did you close the door?

[LearnLang302]

Wow, her voice has major problems on this sentence when it's slow. :D

[MattBush2]

Yeah, 'du' pronounced as 'div' throws me every time.

[DenisSharp]

Why not "have you closed the door"?

[thorr18]

There's a slight difference in tense there. I say that's like "Is your present status that of having closed the door in the past." :)
Those other tenses show up in other parts of the course:
https://www.duolingo.com/skill/sv/Verbs%3A-Past-Perfect

[Thomas-Steve]

Stumbled onto the phrase på glänt this morning. "Ställ dörren på glänt är du snäll!" - Wiktionary. Thought it was worth passing on.

[ax1ax2]

It did not sound like a question to me

[thorr18]

This has to be a question, because the verb comes before the subject. That's the rule in Swedish.