Ef við förum núna, þá náum við strætó.

Ef means if. It introduces a condition:

• Ef við förum núna = If we go now

So the whole sentence has the structure:

• condition
  • result
• Ef ... , þá ... = If ..., then ...

This is a very common pattern in Icelandic.

Yes. Þá here means then.

So:

• Ef við förum núna, þá náum við strætó.
• If we go now, then we’ll catch the bus.

In English, then is often optional in this kind of sentence, and the same is true in Icelandic. You can often say:

• Ef við förum núna, náum við strætó.

That still sounds natural. But þá helps make the result clause clearer and more emphatic.

This is because Icelandic usually follows a verb-second pattern in main clauses.

That means the finite verb normally comes in the second position. In the clause:

• þá náum við strætó

the first element is þá, so the verb náum comes next, and the subject við comes after it.

So the order is:

• þá
  • náum
    • við

not:

• þá
  • við
    • náum

This kind of inversion is very common in Icelandic.

Förum is the 1st person plural present tense form of fara, which means to go.

So:

• ég fer = I go
• þú ferð = you go
• við förum = we go

In this sentence:

• Ef við förum núna = If we go now

Even though English often uses a present form here too, learners sometimes expect a special future form. Icelandic does not need one here.

Náum is the 1st person plural present tense of ná.

Depending on context, ná can mean things like:

• reach
• manage to
• catch

In this sentence, it means catch or make it to in time:

• nán við strætó = we catch the bus / we make the bus

So:

• þá náum við strætó = then we’ll catch the bus

Even though the subject is the same, Icelandic normally states it in both clauses.

So you say:

• Ef við förum núna, þá náum við strætó.

not usually:

• Ef við förum núna, þá náum strætó.

Each clause needs its own subject unless there is some special structure. This is very normal and works much like English:

• If we go now, then we’ll catch the bus.

English also repeats we.

Strætó here is an indefinite/general object: a bus or the bus in a practical sense, depending on context.

In Icelandic, you do not always use the definite article where English might. With transportation, a bare noun is often natural.

So:

• ná strætó = catch a bus / catch the bus
• taka strætó = take the bus

If you said strætóinn, that would sound more specifically like the particular bus. That can be correct in the right context, but the bare form is very common and natural.

Here strætó is the direct object of náum, so it is in the accusative.

The verb ná commonly takes an accusative object when it means reach or catch something.

With strætó, the form often looks the same, so you do not see a visible change here. But grammatically, it is functioning as an accusative object.

This is completely normal in Icelandic.

Icelandic often uses the present tense to talk about the future when the future meaning is clear from context.

So:

• Ef við förum núna, þá náum við strætó.

literally looks like:

• If we go now, then we catch the bus

but naturally means:

• If we go now, then we’ll catch the bus

English does something similar in the if-clause:

• If we go now ... not usually
• If we will go now ...

So this is a good sentence to remember as a normal future-use of the present.

Yes, but only slightly.

Both can mean now.

• nú = now
• núna = now, often a bit more conversational or immediate

In many contexts they are interchangeable. In this sentence:

• Ef við förum núna sounds very natural and everyday

You could also hear:

• Ef við förum nú ...

but núna often feels a little more natural in spoken Icelandic.

Yes, the comma is normal here.

Icelandic commonly uses a comma between a subordinate clause and the main clause:

• Ef við förum núna, þá náum við strætó.

So the comma helps show the break between:

• Ef við förum núna = subordinate clause
• þá náum við strætó = main clause

You will see this punctuation very regularly in written Icelandic.

Yes. That is also a correct and natural sentence.

It just puts the main clause first:

• Við náum strætó ef við förum núna.

This means the same thing as:

• Ef við förum núna, þá náum við strætó.

The version with ef first can feel a little more like you are setting up the condition first. The version with við náum strætó first can feel a little more direct. Both are good Icelandic.