Hann borgar í hvert sinn sem hann fargar byggingarúrgangi.

Yes. Í hvert sinn sem is a very common expression meaning every time that / whenever.

It is best learned as a chunk rather than translated word by word. Icelandic often uses set phrases like this where English might use a shorter expression.

You will also see similar patterns such as:

• í þetta sinn = this time
• í fyrsta sinn = for the first time

So here, í hvert sinn sem introduces a repeated situation: every time the action in the second clause happens, the result in the main clause happens too.

Because hver changes form depending on gender, number, and case.

Here it goes with sinn, which in this expression is a neuter singular noun meaning time / occasion. The phrase requires the accusative singular, so the correct form is hvert.

So:

• hver = dictionary form
• hvert = neuter singular accusative

That is why you get í hvert sinn.

Here sem introduces the subordinate clause after í hvert sinn.

So the structure is:

• í hvert sinn = every time
• sem hann fargar byggingarúrgangi = that he disposes of construction waste

In natural English, we often say every time he... without that, but Icelandic normally uses sem in this pattern.

Because Icelandic normally needs an explicit subject in each clause.

So even though the subject is the same person in both parts, Icelandic still says:

• Hann borgar
• sem hann fargar byggingarúrgangi

English does the same here: He pays every time he disposes...

You generally cannot just leave out the second hann.

Because að farga is a verb that directly takes a dative object in Icelandic.

So:

• að farga einhverju = to dispose of something

There is no separate preposition corresponding to English of here. The idea of dispose of is built into the verb farga, and the noun following it must be in the dative.

This is a very common thing in Icelandic: many verbs require a specific case, and English speakers have to learn the verb and its case pattern together.

Byggingarúrgangi is the dative singular form of byggingarúrgangur.

It is in the dative because the verb farga requires the dative.

So the important pattern is:

• byggingarúrgangur = nominative form
• byggingarúrgangi = dative form

If you are learning Icelandic, it is very useful to memorize nouns together with at least their nominative and one oblique form, because case endings matter a lot.

It is a compound noun meaning construction waste or building waste.

Icelandic very often writes compound nouns as one word, much more consistently than English does. So instead of writing something like building waste as two words, Icelandic combines the parts:

• byggingar- = building / construction
• úrgangur = waste

Together: byggingarúrgangur

In this sentence you see byggingarúrgangi, which is just the dative form required by farga.

The singular is natural because waste is being treated as a mass noun, just as it often is in English.

So construction waste is thought of as a substance or category, not as separate countable items.

A plural could be possible in a different context if you were talking about different kinds of waste or separate waste materials, but in a normal sentence like this, the singular is the expected choice.

Because the sentence describes a habitual or general situation.

It is not talking about one single event happening right now. It means that whenever this situation occurs, this is what happens.

That is why Icelandic uses the present tense:

• borgar = pays
• fargar = disposes

This works much like the English simple present in sentences such as He pays every time he disposes of construction waste.

Because Icelandic main clauses and subordinate clauses do not always use the same word order.

In the main clause, Icelandic usually follows the V2 rule, where the finite verb tends to come early:

• Hann borgar

But after a subordinating word like sem, the clause is normally not V2 in the same way. The usual order is:

• sem hann fargar byggingarúrgangi

So for learners, a good rule is:

• main clause: often V2
• subordinate clause after sem: usually subject before the finite verb

Sometimes, but the meaning would not be exactly the same.

• þegar = when
• í hvert sinn sem = every time / whenever

So í hvert sinn sem clearly emphasizes repetition. It tells you that this happens on each occasion.

If you used þegar, the sentence might sound more neutral or less explicit about the repeated every time idea. In this sentence, í hvert sinn sem is the better choice because repetition is an important part of the meaning.