Hún er ákveðin og dugleg, svo hún heldur áfram þegar eitthvað er erfitt.

Here ákveðin means determined or resolute.

That word can also mean certain or specific in other contexts, so learners often get confused by it. In this sentence, because it describes a person’s character, determined is the natural meaning.

Because it describes hún (she), the adjective has to agree with the subject in gender, number, and case.

Here hún is:

• feminine
• singular
• nominative

So the adjective appears in the feminine singular nominative form: ákveðin.

Dugleg is a very common Icelandic adjective meaning something like:

• hardworking
• diligent
• capable
• good at getting things done

It is often used more broadly than English hardworking. It can describe someone who is energetic, useful, dependable, or good about doing what they should do.

Just like ákveðin, dugleg agrees with hún.

So it is also in the feminine singular nominative form. After er (is), Icelandic predicate adjectives still agree with the subject:

• Hún er dugleg
• Hann er duglegur
• Barnið er duglegt

Here svo means so in the sense of therefore or as a result.

So the sentence structure is:

• She is determined and hardworking
• so she keeps going when something is difficult

Be aware that svo can mean other things too in Icelandic, such as then, so/very, or like this, depending on context.

Because svo hún heldur áfram is a new clause, and Icelandic normally states the subject clearly in that clause.

English also usually does this:

• She is determined and hardworking, so she keeps going...

You would not normally leave out the second she, and Icelandic works the same way here.

Heldur áfram means continues, keeps going, or carries on.

It comes from the expression halda áfram:

• halda = to hold / keep / continue in certain expressions
• áfram = onward / ahead / further

Together, halda áfram is a very common way to say continue.

Halda is the infinitive form, meaning to continue / to hold.

In the sentence, the verb must be conjugated to match hún in the present tense, so you get heldur:

• ég held
• þú heldur
• hún heldur

So hún heldur áfram = she continues / she keeps going.

This verb is not completely regular, so the stem changes from halda to held- in some forms.

Here þegar means when.

It introduces the clause:

• þegar eitthvað er erfitt = when something is difficult

A common point of confusion is that þegar can also mean already in other sentences. For example:

• Hún er þegar farin = She has already left

So the meaning depends on how the word is used in the sentence.

Eitthvað means something.

It is an indefinite pronoun, used when you are not naming a specific thing. In this sentence, it refers generally to any difficult thing or situation:

• þegar eitthvað er erfitt = when something is difficult

Because eitthvað is grammatically neuter singular, and the adjective has to agree with it.

So:

• eitthvað er erfitt = something is difficult

Compare:

• hann er erfiður = he is difficult
• hún er erfið = she is difficult
• það er erfitt = it is difficult

The -tt ending shows the neuter singular form of the adjective.

Yes. After þegar meaning when, Icelandic uses a subordinate clause, and the word order is different from the usual main-clause verb-second pattern.

So you get:

• þegar eitthvað er erfitt

not a main-clause order like:

• þegar er eitthvað erfitt

That makes this a good example of how Icelandic word order changes depending on whether a clause is main or subordinate.