Ef þú ferð héðan núna, nærðu líklega lestinni.

This is very normal in Icelandic.

In sentences like this, Icelandic often uses the present tense to talk about a future result:

• Ef þú ferð héðan núna = If you leave here now
• nærðu líklega lestinni = you will probably catch the train

So even though English often uses will in the main clause, Icelandic usually does not need a separate future tense here. The present tense is enough when the future meaning is clear from context.

Ef means if.

It introduces a conditional clause, just like in English:

• Ef þú kemur = If you come
• Ef það rignir = If it rains

In your sentence:

• Ef þú ferð héðan núna = If you leave here now

So everything after ef sets up the condition for what happens in the main clause.

Because the subject is þú (you, singular).

The verb is fara (to go / leave). In the present tense:

• ég fer = I go
• þú ferð = you go
• hann/hún/það fer = he/she/it goes

So:

• þú ferð = you go / you leave

The -ð ending marks the 2nd person singular here.

Héðan means from here, while hér means simply here.

This is an important Icelandic distinction:

• hér = here
• hingað = to here / here(to)
• héðan = from here

So:

• ferð héðan = go/leave from here

Using héðan makes the sense of movement away from this place very clear.

Yes. Very often, fara héðan is a natural way to say leave here or go away from here.

So although the literal meaning is go from here, in natural English the best translation is often simply:

• leave now
• leave here now

This is a good example of how Icelandic may use a more literal movement expression where English prefers a single verb like leave.

It is written as one word, but historically and grammatically it corresponds to:

• nærð þú = do you catch / you catch

Here:

• nærðu = nærð + þú

This kind of joining happens very commonly in Icelandic when the verb comes before the subject pronoun.

So the underlying parts are:

• nærð = you catch/reach
• þú = you

Together:

• nærðu

This is because of Icelandic word order, especially the verb-second pattern.

The sentence begins with a subordinate clause:

• Ef þú ferð héðan núna = If you leave here now

After that whole clause comes the main clause. In Icelandic, when something else is placed first, the finite verb in the main clause usually comes before the subject:

• nærðu líklega lestinni

rather than:

• þú nærð líklega lestinni

So the order is different because the if-clause comes first.

A rough structural view is:

• [Ef þú ferð héðan núna], [nærðu líklega lestinni].

This inversion is very common in Icelandic.

It comes from the verb ná.

Ná can mean things like:

• reach
• get to
• catch (for example a train, bus, deadline, etc.)
• sometimes manage to

In this sentence, the natural meaning is:

• catch the train

So:

• nærðu lestinni = you catch the train / you make the train

Because the verb ná takes the dative case in this meaning.

The noun is:

• lest = train

With the definite article:

• lestin = the train

But after ná, Icelandic uses the dative:

• lestinni = the train (dative singular)

So:

• ná lestinni = catch the train

This is something learners usually just have to memorize with the verb:

• ná + dative

Líklega means probably.

It is an adverb, and in this sentence it modifies the whole idea of catching the train:

• nærðu líklega lestinni = you will probably catch the train

Its position is very natural in Icelandic. Adverbs like this often come after the finite verb and before the object or complement.

Compare:

• Hann kemur líklega. = He will probably come.
• Þú nærð líklega lestinni. = You will probably catch the train.

In principle, that shows the same grammatical pieces, but in normal written Icelandic the contracted form nærðu is the standard and natural one here.

So learners should mainly get used to seeing and using:

• nærðu

rather than:

• nærð þú

The same thing happens with other verbs too in inverted word order.

The comma separates the if-clause from the main clause:

• Ef þú ferð héðan núna, nærðu líklega lestinni.

This is standard punctuation in Icelandic when a subordinate clause comes first.

So the comma helps show the structure:

1. condition: Ef þú ferð héðan núna
2. result: nærðu líklega lestinni

Both relate to now, but núna often feels a bit more like right now / now at this moment, while nú can sometimes be broader or more flexible depending on context.

In many everyday sentences, they can be quite similar. Here, núna fits very naturally:

• Ef þú ferð héðan núna... = If you leave here now...

It gives a clear immediate sense: this needs to happen at once / right now.

The present tense is the normal and most natural choice here.

Icelandic can express future meaning in other ways when needed, but in ordinary conditionals like this, the present tense usually sounds best:

• Ef þú ferð héðan núna, nærðu líklega lestinni.

That is exactly the kind of sentence where Icelandic prefers the present, even though English often says will probably catch.

So as a learner, it is best to get comfortable with:

• present tense + future meaning from context

A helpful breakdown is:

• Ef = if
• þú = you
• ferð = go / leave
• héðan = from here
• núna = now
• nærðu = catch you / you catch
• líklega = probably
• lestinni = the train (dative)

So structurally:

• Ef + clause, main clause with inversion

That gives:

• Ef þú ferð héðan núna, nærðu líklega lestinni.

A learner-friendly grammar summary would be:

• If-clause first
• then verb-first main clause
• with ná + dative

That combination is what makes the sentence work.