Learn Hardcore Swedish: Efter att gästerna har gått, släcker han ljusen och tänder bara en liten lampa. - After the guests have left, he turns off the candles and only turns on a small lamp.

a preposition:
- efter festen = after the party (followed by a noun phrase)
part of a subordinating conjunction efter att:
- efter att gästerna har gått = after the guests have left (followed by a whole clause with subject + verb)

Because your sentence is followed by a full clause (gästerna har gått), Swedish normally uses efter att.

Compare:

Efter festen släcker han ljusen.
After the party, he turns off the lights. (noun phrase)
Efter att gästerna har gått, släcker han ljusen.
After the guests have left, he turns off the lights. (full clause)

So: efter + noun, but efter att + clause (in standard written Swedish).

Can you leave out att and just say Efter gästerna har gått?

You will hear Efter gästerna har gått in spoken Swedish, but in careful, standard written Swedish it’s usually considered incorrect or at least non‑standard.

The common patterns are:

Efter att gästerna har gått … (most neutral/standard)
Efter att gästerna gått … (drop har, quite common, more written/literary)
Efter gästerna gått … (drop both att and har, more informal/colloquial)

So for learners, the safest choice is:

Efter att gästerna har gått, …

Why is it har gått and not just gick?

Har gått is the present perfect (have gone). It’s used to talk about an action that is completed and whose result is relevant to the following situation.

Efter att gästerna har gått, släcker han ljusen …
After the guests have gone (and are now gone), he turns off the lights…

If you said efter att gästerna gick, it would sound odd here; Swedish normally prefers har + supine (perfect) in this kind of “after X has happened, Y happens” structure.

So: use har gått to emphasize that the leaving is completed before he turns off the lights.

Why is the main verb in the present tense (släcker, tänder) when English would often say “he will turn off / switch on”?

Swedish often uses the present tense for:

habitual actions: what someone usually does
future events, when the context makes the future time clear

Here it sounds like a habitual description:

Efter att gästerna har gått, släcker han ljusen …
= After the guests have gone, he (always/usually) turns off the lights…

If you wanted a specific future time, you could say:

Efter att gästerna har gått, ska han släcka ljusen …
After the guests have gone, he will turn off the lights…

But the sentence as given is perfectly natural Swedish for a general habit.

Why is the word order in gästerna har gått the same as in English, and not inverted like in German?

In Swedish subordinate clauses (introduced by att, eftersom, när, efter att, etc.), the basic order is:

subject – finite verb – rest

So:

gästerna har gått
subject (gästerna) + finite verb (har) + supine (gått)

There is no V2 rule (verb-in-second-position) inside subordinate clauses in Swedish. V2 only applies to main clauses.

So you do not say:
✗ efter att har gästerna gått

You use S–V order, like English:
✓ efter att gästerna har gått

Is the comma after gått necessary?

The comma is normal and recommended here, because a subordinate clause comes first:

Efter att gästerna har gått, släcker han ljusen …

Modern Swedish punctuation rules:

Put a comma between a fronted subordinate clause and the main clause.
You generally don’t put a comma before a subordinate clause at the end of the sentence.

So:

Efter att gästerna har gått, släcker han ljusen.
Han släcker ljusen efter att gästerna har gått. (no comma here)

In informal writing you may sometimes see the comma omitted, but for learners, including it is safest.

What’s the difference between släcker and stänger av for “turn off”?

Both can translate “turn off,” but they’re used in different ways:

släcka
literally: to extinguish; to put out
Typical with: ljus (lights, candles), eld (fire), cigaretter (cigarettes)
- släcka ljuset / ljusen – turn off the light(s)
- släcka stearinljusen – blow out the candles
stänga av
literally: to shut off; to switch off
Typical with: apparater (devices), maskiner, tv:n, datorn
- stänga av tv:n – turn off the TV
- stänga av datorn – shut down the computer

In this sentence, because we’re talking about ljusen (lights / candles), släcker is the natural verb.

What exactly does ljusen mean here, and why is it definite plural?

Ljus can mean:

light (general illumination)
a candle (especially in certain contexts)

Its forms are:

ett ljus – a light / a candle
ljuset – the light / the candle
ljus – lights / candles (indefinite plural)
ljusen – the lights / the candles (definite plural)

In your sentence:

släcker han ljusen = he turns off the lights or he puts out the candles

The definite plural (ljusen) suggests specific, known lights/candles in the room (for example, the ones currently on), not just lights in general.

Can you say tänder en liten lampa bara instead of tänder bara en liten lampa? Where does bara go?

Bara means only and is a sentence adverb. In neutral word order, it normally goes directly before the element it limits.

Han tänder bara en liten lampa.
= It is only one small lamp that he turns on (not more than one).

If you say:

Han tänder en liten lampa bara.

…it sounds more colloquial and adds a slight afterthought or emphasis, a bit like English “He turns on one small lamp, only.” It’s not wrong, but it’s less neutral and can sound stylistic/marked.

For learners, the most natural placement in standard Swedish here is:

tänder bara en liten lampa

Why is it en liten lampa and not en lilla lampa?

Adjectives in Swedish change form depending on definiteness, gender, and number.

For liten (“small / little”) + lampa (“lamp”):

Indefinite singular (common gender):
- en liten lampa – a small lamp
Definite singular:
- den lilla lampan – the small lamp

So:

en liten lampa (indefinite) ✅
den lilla lampan (definite) ✅
en lilla lampa ❌ (mixes indefinite en with definite lilla)

In your sentence, we’re introducing a lamp, not referring to a specific one that both speaker and listener already know, so the indefinite form en liten lampa is correct.

Why do we need han? Can Swedish drop the subject like in some other languages?

Swedish cannot normally drop the subject. You must have an explicit subject pronoun (except in imperatives, like Gå! – “Go!”).

So you say:

Han släcker ljusen … – He turns off the lights … ✅
not
✗ Släcker ljusen … (unless it’s a command: Släck ljusen! – “Turn off the lights!”)

So in your sentence han is required and completely normal.

Could I use när instead of efter att? What’s the difference between Efter att gästerna har gått and När gästerna har gått?

Both are possible, but they’re not identical:

Efter att gästerna har gått, …
After the guests have gone, …
→ Focus on sequence in time: first they leave, then he does something.
När gästerna har gått, …
literally: When the guests have gone, …
→ Often used similarly, meaning “once they’ve gone / as soon as they have gone”.
There is still an idea of “after,” but it’s slightly less explicit than efter att.

In many contexts, both are acceptable with only a slight nuance. Efter att is more precise about “later / afterwards”; när is broader (“when/once”).

Could the sentence describe a single future event, or is it always habitual?

On its own, in present tense, it most naturally sounds habitual:

Efter att gästerna har gått, släcker han ljusen …
= After the guests have gone, he (normally) turns off the lights…

To make a specific future event clearer, Swedish often adds a future marker like ska:

Efter att gästerna har gått, ska han släcka ljusen och tända bara en liten lampa.
= After the guests have gone, he will turn off the lights and turn on only a small lamp.

So: present alone can be future in context, but if you want to emphasize a single planned future occurrence, ska makes it explicit.