Vi passade på att ta en promenad innan regnet kom.

Passa på is a very common Swedish expression meaning to take the opportunity, to make the most of the moment, or to seize the chance.

So Vi passade på att ta en promenad means something like:

• We took the opportunity to go for a walk
• We made the most of the chance to take a walk

It often suggests that the opportunity might disappear soon — which fits well with innan regnet kom.

Passade is the past tense of passa.

• passar = present tense
• passade = past tense

Since the whole sentence describes something that already happened, Swedish uses the past tense:

• Vi passade på ... = We took the opportunity ...
• ... innan regnet kom = ... before the rain came

So both main actions are in the past.

Because passa på is a fixed expression. The på is not optional here.

Compare:

• passa can have other meanings, such as fit or suit
• passa på specifically means take the opportunity

So:

• passa ≠ passa på
• they are understood as different expressions

You should learn passa på as a unit.

After passa på, Swedish normally uses att + infinitive to say what opportunity was taken.

Pattern:

• passa på att + infinitive

Examples:

• Jag passade på att vila. = I took the opportunity to rest.
• Hon passade på att fråga. = She took the opportunity to ask.

So in your sentence:

• passade på att ta en promenad = took the opportunity to take/go for a walk

This is the standard construction.

Swedish often uses ta en promenad, literally take a walk, just like English can.

• ta en promenad = take a walk / go for a walk
• promenera = walk / go for a walk

So both are possible:

• Vi passade på att ta en promenad
• Vi passade på att promenera

But ta en promenad often sounds very natural and idiomatic in everyday Swedish.

Promenad is a common-gender noun, so it takes en:

• en promenad = a walk
• promenaden = the walk

In the sentence, it is an indefinite noun phrase:

• ta en promenad = take a walk

This is similar to English, where you also usually say take a walk, not take walk.

Because innan introduces a subordinate clause: before the rain came.

In Swedish subordinate clauses, the word order is normally:

• conjunction + subject + verb

So:

• innan regnet kom
• innan han gick
• innan vi åt

That is normal Swedish word order in a subordinate clause.

A learner may expect inversion because Swedish often has verb-second word order in main clauses, but subordinate clauses do not follow that same pattern.

Regnet means the rain.

Swedish often uses the definite form where English might simply say rain, especially when talking about a specific, expected event in the situation.

So:

• innan regnet kom = before the rain came

This sounds natural because it refers to the rain that was about to arrive, not rain in general.

If you said innan regn kom, it would sound wrong in standard Swedish.

Because simple past is enough here.

• kom = came
• hade kommit = had come

In Swedish, after innan (before), it is very common to use the simple past when the sequence is already clear from context.

So:

• Vi passade på att ta en promenad innan regnet kom.

clearly means:

• first: we took a walk
• then: the rain came

You could use more complex tense forms in some contexts, but here kom is the natural, ordinary choice.

Yes, absolutely.

Two natural versions are:

• innan regnet kom = before the rain came
• innan det började regna = before it started raining

They are very close in meaning, but there is a slight difference in feel:

• regnet kom focuses on the arrival of the rain
• det började regna focuses on the moment it started raining

Both are idiomatic.

Yes, very common.

Swedes often use passa på when they want to say they did something because the timing was good.

Examples:

• Vi passade på att handla när butiken var tom.
  We took the opportunity to shop when the store was empty.

• Jag passade på att fråga henne.
  I took the chance to ask her.

• De passade på att åka utomlands innan priserna steg.
  They took the opportunity to travel abroad before prices went up.

So this sentence sounds very natural and everyday.

It is a time clause.

It tells you when the action in the main clause happened:

• Main clause: Vi passade på att ta en promenad
• Time clause: innan regnet kom

So the full idea is:

• We took the opportunity to go for a walk
• before the rain came

This kind of structure is very common in Swedish: main clause + innan clause.

Yes. You can also start with the innan clause:

• Innan regnet kom passade vi på att ta en promenad.

Notice what happens in the main clause after the fronted clause:

• Innan regnet kom
  • passade vi på ...

The verb passade comes before the subject vi because Swedish main clauses follow the verb-second rule.

So both are correct:

• Vi passade på att ta en promenad innan regnet kom.
• Innan regnet kom passade vi på att ta en promenad.

The meaning stays basically the same.