Ég hreinsa lyklaborðið áður en ég byrja að vinna, því það er skítugt.

Because lyklaborðið means the keyboard, while lyklaborð means a keyboard or just keyboard in a general sense.

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

• lyklaborð = keyboard
• lyklaborðið = the keyboard

So in this sentence, the speaker is talking about a specific keyboard.

It is the accusative singular, because it is the direct object of hreinsa.

The verb hreinsa means to clean, and the thing being cleaned is the object:

• Ég hreinsa lyklaborðið = I clean the keyboard

A useful detail: for many neuter singular nouns, the nominative and accusative forms are the same, so even though it is accusative here, it looks the same as nominative.

Áður en means before when followed by a full clause.

So:

• áður en ég byrja að vinna = before I start working

This is different from just using a simple preposition before a noun phrase. Here, áður en introduces another clause with its own subject and verb:

• ég = subject
• byrja = finite verb

Because Icelandic, like English, normally needs a subject in each clause.

The sentence has more than one clause:

1. Ég hreinsa lyklaborðið
2. áður en ég byrja að vinna
3. því það er skítugt

In the second clause, the subject is still I, but Icelandic still says it explicitly:

• áður en ég byrja... = before I start...

You cannot just leave ég out here.

After byrja (to begin / to start), Icelandic normally uses að + infinitive.

So:

• byrja að vinna = start to work / start working

Here að is the infinitive marker, similar to English to in to work.

This pattern is very common in Icelandic:

• byrja að lesa = start reading
• halda áfram að tala = continue speaking
• reyna að skilja = try to understand

Because after að, you normally use the infinitive form of the verb.

The infinitive of the verb is vinna = to work.

Compare:

• ég vinn = I work
• ég vann = I worked
• að vinna = to work / working

So in byrja að vinna, the speaker is not saying a fully conjugated second verb; they are using the infinitive after að.

Byrja is the indicative form, while byrji is subjunctive.

In a sentence like this, áður en can sometimes be followed by either mood depending on meaning and style. The indicative often appears when the action is presented as real, regular, or factual. This sentence sounds like a habitual action:

• I clean the keyboard before I start working...

So áður en ég byrja að vinna is natural.

You may also encounter subjunctive after áður en, especially when the action is more future-oriented or uncertain:

• áður en ég byrji að vinna

For a learner, the safest takeaway is:

• byrja here is perfectly normal
• byrji is also something you may see in other contexts

Here því is a conjunction meaning because / since.

So:

• því það er skítugt = because it is dirty

A beginner often first learns af því að for because, and that would also work:

• ... af því að það er skítugt

Compared with af því að, plain því can sound a bit more compact or written-style, though it is very common and natural.

Also, in this sentence, the comma before því is normal.

Það refers to lyklaborðið (the keyboard).

Since lyklaborð is a neuter noun, the pronoun referring back to it is also neuter:

• það = it

So:

• lyklaborðið ... það = the keyboard ... it

This is an example of normal agreement in gender.

Because the adjective has to agree with the word it describes.

Here skítugt describes það, which refers to lyklaborðið, a neuter singular noun. So the adjective must also be neuter singular:

• skítugur = masculine singular
• skítug = feminine singular
• skítugt = neuter singular

That is why the sentence says:

• það er skítugt = it is dirty

Yes, hreinsa is a good and natural verb here. It means clean, clear, or remove dirt from something.

Another common verb is þrífa, which can also mean clean. In many everyday situations, both are possible, though they can differ a bit in nuance depending on context.

For this sentence:

• Ég hreinsa lyklaborðið... = natural
• Ég þríf lyklaborðið... = also possible

A simple learner-friendly way to think about it:

• hreinsa often focuses on making something clean or clearing something away
• þrífa is also a very common everyday word for cleaning

This sentence has both:

• þ in því
• ð in lyklaborðið

A rough guide for English speakers:

• þ is like the th in thin
• ð is like the th in this

So approximately:

• því sounds a bit like thvee
• lyklaborðið ends with a sound like -rthith or -rthid, depending on how precisely you hear it

One important point: Icelandic ð often sounds softer than English speakers expect, and in some positions it may be weak or reduced. But as a starting point, thinking of it as the voiced th in this is helpful.

Yes. If you move the áður en... clause to the front, the main clause normally shows the usual Icelandic verb-second pattern.

Original:

• Ég hreinsa lyklaborðið áður en ég byrja að vinna, því það er skítugt.

With the time clause first:

• Áður en ég byrja að vinna, hreinsa ég lyklaborðið, því það er skítugt.

Notice the change:

• Ég hreinsa... becomes hreinsa ég...

That inversion is very typical in Icelandic main clauses after something has been placed first.