Sluk lyset med lyskontakten, før du går, og prøv ikke at rive i håndtaget.

Because Sluk is the imperative form: the form used for commands.

• slukke = to turn off
• sluk! = turn off!

In Danish, commands usually omit the subject just like English does:

• Sluk lyset. = Turn off the light.
• Kom her. = Come here.
• Vent lidt. = Wait a moment.

So Sluk lyset is the natural way to give an instruction.

Those endings are the definite article attached to the noun. Danish usually puts the at the end of the noun instead of using a separate word.

The ending depends on the noun’s gender:

• et lys → lyset = the light
• et håndtag → håndtaget = the handle
• en lyskontakt → lyskontakten = the light switch

So:

• -et is common for definite neuter nouns
• -en is common for definite common gender nouns

English speakers often notice this quickly because Danish says light-the, handle-the, switch-the, not a separate word like the.

Because Danish normally writes compound nouns as a single word.

Here:

• lys = light
• kontakt = switch/contact

Together they form:

• lyskontakt = light switch

Then the definite ending is added:

• lyskontakten = the light switch

This is very common in Danish. English often writes such things as two words, but Danish usually joins them:

• toothbrush-type logic is very common in Danish
• for example: dørhåndtag = door handle, soveværelse = bedroom

Here med means with / by means of / using.

So Sluk lyset med lyskontakten means you should turn off the light using the light switch.

It marks the instrument used to do the action. Compare:

• Jeg skriver med en blyant. = I write with a pencil.
• Åbn den med nøglen. = Open it with the key.

In this sentence, med lyskontakten adds the idea use the switch, not some other method.

Because før du går is a subordinate clause, and Danish subordinate clauses usually keep subject + verb order.

So:

• du går = you go / you leave

After conjunctions like før, fordi, når, hvis, and at, Danish normally uses this order:

• før du går
• fordi han er træt
• når vi kommer

English speakers sometimes expect inversion, but Danish does not do that here.

Går is the present tense of gå.

• gå = to go / to walk / to leave, depending on context
• du går = you go / you are leaving

In før du går, Danish uses the present tense in the same kind of way English often does in time clauses:

• before you leave
• not usually before you will leave

So før du går is perfectly normal Danish.

Because ikke negates the infinitive phrase that follows prøv.

Structure:

• prøv = try
• ikke at rive = not to pull/tug

So the full idea is:

• Prøv ikke at rive i håndtaget. = Try not to pull on the handle.

This is a natural Danish structure when prøve is followed by an infinitive.

Compare:

• Prøv at vente. = Try to wait.
• Prøv ikke at grine. = Try not to laugh.

If you moved ikke, the meaning or tone could change.

Because after prøve, Danish normally uses at + infinitive.

• prøve at gøre noget = try to do something

So:

• prøv at åbne døren = try to open the door
• prøv ikke at rive i håndtaget = try not to pull on the handle

This is very common and standard.

That is a very good question. By itself, rive often does mean tear, rip, or scratch depending on context. But rive i is a different expression.

In this sentence, rive i håndtaget means something like:

• pull at the handle
• yank on the handle
• tug at the handle

So the preposition i matters. It changes the feel of the verb from simply tear to pull/tug at something, often a bit roughly.

That is why it is important to learn some Danish verbs together with their prepositions, not only as single words.

Because the expression is rive i noget.

The i is part of the pattern:

• rive i døren
• rive i armen
• rive i håndtaget

It suggests pulling or tugging at/on something. Without i, the meaning would not be the same and could sound wrong or mean something else.

So here i is not optional; it belongs to the expression.

Because før du går is inserted into the sentence as a subordinate clause:

• Sluk lyset med lyskontakten, før du går, og prøv ikke at rive i håndtaget.

The commas show where that inserted clause begins and ends.

Also, there is a comma before og because the sentence then continues with another main clause/command:

• Sluk ...
• og prøv ...

A small extra note: in Danish, comma practice can vary a little depending on whether someone uses start comma or not. So you may sometimes see a version without the first comma before før. But the sentence as written is perfectly standard and clear.