Eftir því sem uppskeran verður meiri vinnur garðyrkjumaðurinn meira.

It is a fixed expression meaning as, the more, or in proportion as.

In this sentence, Eftir því sem ... meira gives the idea:

• As the harvest gets bigger, the gardener works more
• The greater the harvest, the more the gardener works

It is a very common way in Icelandic to express a gradual relationship between two things.

Yes, very often it is.

This sentence corresponds naturally to the English comparative pattern:

• The bigger the harvest gets, the more the gardener works

Icelandic does not always copy the English the more ..., the more ... structure word for word. Instead, Eftir því sem is one standard way to express that same idea.

Here því is part of the fixed expression eftir því sem. You do not need to analyze it every time as a fully independent word choice; learners usually do best by memorizing the whole chunk.

That said:

• því is the dative form of það
• eftir often takes the dative in expressions like this

But the most useful thing is simply:

• learn eftir því sem as one unit meaning as / the more / in proportion as

Sem is a very common connector in Icelandic. In this expression, it helps introduce the clause that follows.

So in:

• Eftir því sem uppskeran verður meiri ...

the part after sem is the clause describing the changing situation: the harvest becomes greater.

Again, the simplest approach is to learn the whole phrase eftir því sem together.

Because -n at the end is the definite article attached to the noun.

• uppskera = a harvest / harvest
• uppskeran = the harvest

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

So:

• uppskeran verður meiri = the harvest becomes bigger / greater

Because meiri is an adjective agreeing with uppskeran.

Here:

• uppskera is a feminine singular noun
• the adjective must match it
• so Icelandic uses meiri here

This is a predicate adjective after verða (to become), but it still agrees with the subject.

So:

• uppskeran verður meiri = the harvest becomes greater

Because meira here is not describing a noun. It is functioning adverbially and means more in the sense of to a greater extent.

Compare:

• meiri uppskera = a bigger harvest
  
  • adjective, agreeing with a feminine noun
• vinnur meira = works more
  
  • adverb-like use, modifying the verb vinnur

So the difference is:

• meiri = adjective form here
• meira = adverbial comparative form here

That is one of the most important things to notice in this sentence.

Verður is the present tense of verða, which often means become.

So:

• uppskeran verður meiri = the harvest becomes greater / gets bigger

This is different from simply saying that the harvest is big. It suggests a change or increase.

This is because of Icelandic word order, especially the V2 rule in main clauses.

The sentence begins with the subordinate clause:

• Eftir því sem uppskeran verður meiri

After that, the main clause begins. In Icelandic main clauses, the finite verb usually comes in the second position. Since the first position is already taken by the opening clause, the verb comes next:

• vinnur
• then garðyrkjumaðurinn

So:

• Eftir því sem uppskeran verður meiri, vinnur garðyrkjumaðurinn meira

This is normal Icelandic structure.

It is nominative singular, because it is the subject of vinnur.

Breakdown:

• garðyrkjumaður = gardener
• garðyrkjumaðurinn = the gardener

It is a masculine noun with the definite article attached.

Yes, that is a very good way to think about it.

Structurally, it is:

• garðyrkjumaður = gardener
• -inn = the

But in reading, it is often easiest to process the full form directly as:

• garðyrkjumaðurinn = the gardener

Almost, but in natural English it is usually better as:

• the harvest becomes greater
• the harvest gets bigger
• the yield increases

Icelandic meiri can correspond to English more, greater, or bigger, depending on context.

With something like uppskera (harvest / yield), English often prefers greater or bigger rather than the literal-sounding more.

Yes. That is probably the most natural English rendering.

Even though the Icelandic wording is different, the meaning is essentially:

• The bigger the harvest, the more the gardener works

That captures the comparative relationship very well.

Icelandic punctuation does not always match English punctuation exactly. A comma may or may not appear depending on style, tradition, and how the sentence is structured.

You may also see a version with a comma:

• Eftir því sem uppskeran verður meiri, vinnur garðyrkjumaðurinn meira.

So the lack of a comma here is not something to worry too much about as a learner.

A useful way to see it is:

• Eftir því sem X verður meiri, Y vinnur meira

In this actual sentence:

• X = uppskeran
• Y = garðyrkjumaðurinn

So:

• As X becomes greater, Y works more

This is a good pattern to remember for making similar sentences.