Om du diskar nu, torkar jag bordet.

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

Here, the sentence starts with the subordinate clause Om du diskar nu. After that, the main clause begins, and its finite verb torkar must come before the subject jag:

• Om du diskar nu, torkar jag bordet.

If you start with the main clause instead, then normal subject-verb order appears:

• Jag torkar bordet om du diskar nu.

So the word order changes because of what comes first.

Swedish often uses the present tense for future meaning when the context makes it clear.

So:

• Om du diskar nu, torkar jag bordet.

can mean something like:

• If you do the dishes now, I’ll wipe the table.

This is very natural in Swedish, especially in everyday speech, plans, agreements, and conditions.

If you want to make the future meaning more explicit, you could also say:

• Om du diskar nu, ska jag torka bordet.

But the original version is completely normal.

Because om means if, while när means when.

Use om when something is conditional:

• Om du diskar nu, torkar jag bordet. = I’ll do it if you do your part.

Use när when something is treated as expected or certain:

• När du diskar, torkar jag bordet. = When you do the dishes, I wipe the table.

So in your sentence, om is correct because the speaker is making a condition or a deal.

The verb diska commonly means to do the dishes / wash up.

In Swedish, it is very common to use diska without saying exactly what is being washed, because the meaning is already understood.

So:

• du diskar means
• you do the dishes / you wash up

If you want to mention the object, you can:

• du diskar tallrikarna = you wash the plates

But in everyday speech, leaving the object out is very natural.

Nu means now, and it makes the condition more immediate:

• Om du diskar nu... = If you do the dishes now...

It suggests right now / at this moment / without waiting.

Its position here is natural and neutral. If you move nu, the nuance can change a little. For example:

• Om du nu diskar...

can sound more like if you actually are doing the dishes or if you’re going to do the dishes after all, which is a different tone.

So in your sentence, nu is simply marking time.

In Swedish, the definite article is often attached to the end of the noun.

So:

• bord = table
• ett bord = a table
• bordet = the table

That -et ending is the definite form.

So torkar jag bordet literally contains the table in one word.

Yes.

You can say:

• Om du diskar nu, torkar jag bordet.
• Jag torkar bordet om du diskar nu.

Both are correct.

The difference is mostly about focus:

• Starting with Om du diskar nu puts the condition first.
• Starting with Jag torkar bordet puts the speaker’s action first.

Also notice that when the main clause comes first, you get normal word order:

• Jag torkar not
• torkar jag

Not necessarily.

In modern Swedish, the comma before the main clause in a sentence like this is often optional:

• Om du diskar nu torkar jag bordet.
• Om du diskar nu, torkar jag bordet.

Both can be seen.

Many writers include the comma to make the sentence easier to read, especially after a clause at the beginning. Others leave it out. So the comma is not the most important thing here; the word order is.

Yes, sometimes, especially in speech or informal style:

• Om du diskar nu, så torkar jag bordet.

This can sound a little more conversational or slightly more emphatic.

But in neutral written Swedish, it is very common to leave så out:

• Om du diskar nu, torkar jag bordet.

So så is possible, but not necessary.

It is grammatically a conditional sentence, but in everyday use it often sounds like a practical agreement or division of tasks.

So it can feel like:

• If you do the dishes now, I’ll wipe the table.

But also like:

• You do that, and I’ll do this.

That is a very common use of om-sentences in Swedish conversation.