Om strömmen försvinner igen, tänder vi stearinljus i vardagsrummet.

Om means if and introduces a condition:

• Om strömmen försvinner igen = If the power goes out again

In Swedish, om is commonly used to make if-clauses, just like in English.

Examples:

• Om det regnar, stannar vi hemma. = If it rains, we stay home.
• Om du vill, kan jag hjälpa dig. = If you want, I can help.

Strömmen is the definite form of ström.

Here, strömmen means the power/electricity. Swedish often uses the definite form where English also says the.

• ström = power / current
• strömmen = the power / the electricity

The definite ending -en is attached to the noun instead of using a separate word like English the.

So:

• strömmen försvinner = the power disappears / goes out

In this context, strömmen usually refers to the electricity supply.

Yes, försvinner literally means disappears, but in this context it is the natural Swedish way to say that the power goes out.

• försvinna = to disappear
• försvinner = disappears / is disappearing

So although the literal meaning is something like the power disappears, the natural English translation is usually the power goes out.

You may notice that Swedish often uses a more literal verb than English would in the same situation.

Igen means again.

• Om strömmen försvinner igen = If the power goes out again

It comes after the verb försvinner, which is a very natural position in Swedish.

Compare:

• Han kommer igen. = He is coming again.
• Det händer igen. = It happens again.

In this sentence, igen tells us that this has happened before and might happen another time.

This is because Swedish follows the V2 rule in main clauses: the finite verb must come in the second position.

The sentence begins with an if-clause:

• Om strömmen försvinner igen

After that whole clause, the main clause starts. Since the if-clause takes the first position, the finite verb in the main clause must come next:

• tänder vi stearinljus i vardagsrummet

So the word order is:

1. Om strömmen försvinner igen
2. tänder
3. vi

This is very common in Swedish.

Compare:

• I dag arbetar jag hemma.
  not I dag jag arbetar hemma
• Om du kommer, blir jag glad.

If the main clause stood alone, it would be:

• Vi tänder stearinljus i vardagsrummet.

But after the initial conditional clause, it becomes:

• Om strömmen försvinner igen, tänder vi stearinljus i vardagsrummet.

Swedish often uses the present tense to talk about the future, especially when the future is clear from the context.

So:

• Om strömmen försvinner igen, tänder vi stearinljus...

is literally in the present tense, but it means something like:

• If the power goes out again, we’ll light candles...

This is normal and very common in Swedish.

Examples:

• Jag kommer i morgon. = I’m coming tomorrow.
• Om det blir kallt, stänger vi fönstret. = If it gets cold, we’ll close the window.

So you do not need a special future form here.

Tänder is the present tense of tända, which means to light, to switch on, or to ignite, depending on the object.

Here:

• tända stearinljus = light candles

Other examples:

• tända lampan = turn on the lamp
• tända en cigarett = light a cigarette
• tända ett ljus = light a candle

So the exact English translation depends on what is being lit or switched on.

Stearinljus specifically means stearin candles or, in normal English, just candles.

Swedish also has the word ljus, which can mean:

• light
• candle
• something bright

Because ljus has several meanings, Swedish sometimes uses a more specific word like stearinljus to make it clear that actual candles are meant.

So:

• ljus can sometimes be enough from context
• stearinljus is more specific

In everyday Swedish, both can occur depending on context and style.

Because stearinljus is being used in a general plural sense.

• Vi tänder stearinljus = We light candles

This is similar to English, where you can say:

• We light candles without saying
• We light some candles or the candles

If Swedish wanted to be more specific, it could say:

• vi tänder några stearinljus = we light some candles
• vi tänder stearinljusen = we light the candles

But in this sentence, the general plural is completely natural.

Swedish usually uses i for being in a room or enclosed space.

• i vardagsrummet = in the living room

So:

• i köket = in the kitchen
• i sovrummet = in the bedroom
• i vardagsrummet = in the living room

På is used in other kinds of locations, but not normally for rooms in this kind of sentence.

Vardagsrummet is the definite form of vardagsrum.

• vardagsrum = living room
• vardagsrummet = the living room

Swedish adds the definite ending to the noun:

• -et here marks the neuter definite singular

So:

• i vardagsrummet = in the living room

This suggests a specific living room, probably the one in the speaker’s home.

The comma is acceptable and helpful, especially because the sentence begins with a fairly long if-clause.

• Om strömmen försvinner igen, tänder vi stearinljus i vardagsrummet.

In Swedish, commas are often used a bit less rigidly than in English, but in a sentence like this, the comma makes the structure clearer.

You may sometimes see similar sentences without a comma, especially in less formal writing, but with a fronted conditional clause, the comma is very common and useful.

Yes. You could also say:

• Vi tänder stearinljus i vardagsrummet om strömmen försvinner igen.

That has the same basic meaning.

The difference is mostly about focus and word order:

• Starting with Om... puts the condition first.
• Starting with Vi tänder... puts the action first.

Notice that when the main clause comes first, the normal word order returns:

• Vi tänder not
• Tänder vi

That is because nothing else is occupying the first position in the main clause.