After (efter att)

After: Efter att

When you want to describe an event that happens after another event, you can use the subordinating conjunction efter att (after).

after (conjunction)
efter att

Because efter att explicitly connects two events occurring at different times, Swedish strictly requires tense sequencing. The action in the efter att clause must be in a "completed" tense relative to the main clause.

Present and Present Perfect

If the action in the main clause takes place in the present tense, the action in the efter att clause must have already happened. Therefore, it takes the present perfect tense (har + supine verb).

The butterfly flies away after it has unfolded its wings.
Fjärilen flyger iväg efter att den har vecklat ut sina vingar.

Past and Past Perfect

Similarly, if the main action took place in the past (simple past), the event in the efter att clause happened even further back in time. In this case, the efter att clause must use the past perfect tense (hade + supine verb).

The caterpillar reached the second stage after it had eaten a lot.
Larven nådde det andra stadiet efter att den hade ätit mycket.
The researcher examined the cocoon after it had fallen from the branch.
Forskaren undersökte kokongen efter att den hade fallit från grenen.

Shifting Focus with the V2 Rule

Like most subordinate clauses, an efter att clause can be placed at the very beginning of the sentence to shift the emphasis to the timeline.

Remember the golden V2 (verb-second) rule: when the entire sentence begins with a subordinate clause, that clause counts as the first block of information. The main clause that immediately follows must undergo inversion, starting directly with its conjugated verb.

Here is how that looks with a present tense main clause:

After the caterpillar has grown, it transforms into a pupa.
Efter att larven har vuxit, förvandlar den sig till en puppa.

And here is how the V2 rule applies when dealing with past tense actions:

After the pupa had hung in the tree for a long time, a butterfly crawled out.
Efter att puppan hade hängt i trädet länge, kröp en fjäril ut.