Vextirnir á þessu láni eru núna lægri en í fyrra.

In Icelandic, vextir is very often used as a plural noun when talking about financial interest or interest rates.

So:

• vextir = interest / interest rates
• vextirnir = the interest / the interest rates

This is one of those places where Icelandic and English do not match word-for-word. Even if English uses singular interest, Icelandic commonly uses plural vextir.

In Icelandic, the definite article is usually attached to the end of the noun instead of appearing as a separate word.

So:

• vextir = interest rates
• vextirnir = the interest rates

The ending -nir here contains the definite article. This is very common in Icelandic.

Because the subject vextirnir is plural.

• er = is
• eru = are

So:

• Vextirnir ... eru ... = The interest rates ... are ...

Icelandic verbs agree with the subject in number, so a plural subject takes eru.

Literally, á often means on, but prepositions do not always translate neatly between languages.

In this sentence, á þessu láni means something like:

• on this loan
• or more naturally in English, for this loan

So the phrase refers to the interest associated with that loan. This is a normal Icelandic way to express it.

Because the preposition á takes the dative here.

There is no movement involved; it is a static relationship, so Icelandic uses the dative after á in this kind of phrase.

That gives:

• þessi → þessu
• lán → láni

Also, þessi has to agree with lán in gender, number, and case:

• lán is neuter
• it is singular
• after á here it is dative

So þessu láni is the correct form.

Lægri is the comparative form of lágur, which means low.

So:

• lágur = low
• lægri = lower

In this sentence, it describes vextirnir, so it means lower:

• eru núna lægri = are now lower

This is similar to English adjective comparison, but Icelandic usually forms the comparative as a changed adjective form rather than using a separate word like more.

This is a normal comparative structure in Icelandic.

• en = than
• í fyrra = last year

So lægri en í fyrra means lower than last year.

Icelandic, like English, often leaves out repeated material when it is obvious. The full idea is something like:

• lower than they were last year

But Icelandic does not need to repeat all of that. En í fyrra is enough.

Also, í fyrra is a fixed expression meaning last year, so it is worth memorizing as a chunk.

Núna means now or currently. It shows that the lower interest is true at the present time.

So:

• eru lægri = are lower
• eru núna lægri = are now lower

Its position is natural here: after the verb and before the adjective. That is a very common place for adverbs like núna.

You may also see nú in Icelandic, which can also mean now, but núna is very common in everyday speech and often sounds a little more explicit or conversational.