Ég get skrifað, en úlnliðurinn minn er enn stífur eftir langan dag við tölvuna.

Both can relate to English can, but they are not used the same way.

• geta = be able to, manage to, be physically/circumstantially capable of
• kunna = know how to, have learned to

So:

• Ég kann að skrifa = I know how to write
• Ég get skrifað = I can / am able to write

In this sentence, the speaker is talking about physical ability after a long day at the computer, so get is the natural choice.

After geta, Icelandic normally uses the supine form of the main verb, not the infinitive.

So the dictionary form is:

• að skrifa = to write

But after geta it becomes:

• get skrifað = can write

And you do not use að here.

More examples:

• Ég get farið = I can go
• Ég get lesið = I can read
• Ég get unnið = I can work

This is one of the things that feels unusual to English speakers at first.

Úlnliðurinn breaks down like this:

• úlnliður = wrist
• -inn = the suffixed definite article, so the

So úlnliðurinn means the wrist.

Icelandic usually attaches the to the end of the noun instead of putting a separate word in front like English does.

So:

• úlnliður = wrist
• úlnliðurinn = the wrist

In Icelandic, possessives very often come after a definite noun:

• úlnliðurinn minn = my wrist
• literally: wrist-the my

This is the normal, natural pattern.

If you put the possessive first, as in minn úlnliður, it usually sounds more emphatic, contrastive, or literary.

So for ordinary everyday speech, úlnliðurinn minn is exactly what you would expect.

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

Here the noun is úlnliðurinn, which is:

• masculine
• singular
• nominative

So the adjective must also be masculine singular nominative:

• stífur = stiff

Compare:

• úlnliðurinn er stífur = the wrist is stiff
• höndin er stíf = the hand is stiff
• hnéð er stíft = the knee is stiff

So the ending changes depending on the gender of the noun.

Here enn means still.

So:

• er enn stífur = is still stiff

That means the stiffness has continued up to now.

In other contexts, enn can also correspond to English yet, especially in negatives or questions, but in this sentence still is the right sense.

That is the normal placement in a sentence like this.

• er enn stífur = is still stiff

The adverb enn comes before the adjective or complement that it modifies.

That word order is very natural in Icelandic. English does something similar:

• is still stiff

So this part of the sentence is actually fairly close to English structure.

Because eftir requires a different case here.

In this sentence, eftir is followed by the accusative, so:

• langur dagur = a long day (nominative, dictionary-style form)
• langan dag = a long day (accusative)

Both the adjective and the noun change:

• langur → langan
• dagur → dag

So eftir langan dag means after a long day.

Because the meaning is after a long day, not after the long day.

It is indefinite, just like in English.

So:

• langan dag = a long day
• langan daginn would be trying to make it definite, which would change the meaning and sound wrong here

The sentence is referring to the general experience of having had a long day, not to one previously identified specific day.

Because við is the preposition used here for at/by the computer, and tölvuna is the accusative definite form of tölva.

Breakdown:

• tölva = computer
• tölvuna = the computer

So:

• við tölvuna = at the computer / by the computer

This is a very natural Icelandic phrase for working or spending time at a computer.

Not necessarily.

Just like English at the computer, it often means:

• working on the computer
• sitting at the computer
• spending time using the computer

So in langan dag við tölvuna, the idea is a long day spent at the computer, not just physically being beside it.

Because en means but, and here it joins two full clauses:

• Ég get skrifað
• úlnliðurinn minn er enn stífur eftir langan dag við tölvuna

Putting a comma before en is standard and natural in a sentence like this.

So the structure is:

• I can write, but my wrist is still stiff ...

Very similar to English punctuation.