Með smá heppni kemur lestin á réttum tíma í dag.

Because Icelandic main clauses usually follow the V2 rule: the finite verb comes in the second position.

Here, Með smá heppni is placed first, so kemur has to come next:

• Með smá heppni = first element
• kemur = second-position verb
• lestin = subject

If you started with the subject instead, you would get Lestin kemur ...

Með normally takes the dative case, so heppni is grammatically dative here.

A useful thing to know is that the form heppni looks the same in more than one case, so the case is not obvious just from the ending. But after með, learners should expect dative.

Smá means a little, a bit of, or small in a very common everyday way.

In this sentence, smá heppni means a bit of luck. Native-English-speaking learners often expect a fully inflected adjective here, but smá is very often used as an indeclinable modifier in modern Icelandic, so it stays smá instead of changing form.

Icelandic usually puts the definite article onto the end of the noun instead of using a separate word like English the.

So:

• lest = train
• lestin = the train

That final -in is the definite article attached to the noun.

Lestin is nominative singular, because it is the subject of the sentence.

Even though it comes after the verb because of Icelandic word order, it is still the subject. English learners sometimes assume the first noun after the verb must be an object, but that is not how Icelandic works here.

Yes, kemur is the 3rd person singular present tense of koma.

Icelandic often uses the present tense for scheduled, expected, or near-future events, just like English does in sentences such as The train arrives at 5 or The bus leaves tomorrow. So here it can naturally refer to a train arriving later today.

Yes, koma literally means come, but Icelandic also uses it very naturally where English would often say arrive.

So:

• Lestin kemur can mean The train comes
• but in normal English we would usually say The train arrives

This is a very common Icelandic usage.

Á réttum tíma is the normal Icelandic expression for on time or at the right time.

It is best learned as a fixed phrase. The preposition á here goes with the dative, which is why the adjective shows the dative form réttum.

Because Icelandic adjectives have to agree with the noun they describe in gender, number, and case.

Here, réttum describes tíma, and the phrase is dative singular masculine, so the adjective takes the form réttum.

This is one of the big differences from English: Icelandic adjectives change form a lot.

Í dag is the standard Icelandic expression for today.

Grammatically, it contains:

• í = a preposition
• dag = a case form of dagur (day)

In this expression, dag is the accusative singular form. But for learners, the most useful approach is simply to memorize í dag as a very common time expression.

Yes, in practice it works a lot like an idiomatic phrase.

Literally it means with a bit of luck, but in real usage it often has the feel of:

• if we’re lucky
• with any luck
• hopefully

So the sentence does not just state a fact about luck; it also sets the speaker’s attitude toward the situation.

Yes. The core statement is Lestin kemur á réttum tíma í dag.

By putting Með smá heppni first, the speaker gives that idea special emphasis. In other words, the sentence starts by signaling this will happen only if we’re lucky. That fronting is very natural in Icelandic.