Hún man PIN-númerið sitt alltaf, en kortalesarinn virkar samt stundum illa.

Yes. man is the 3rd person singular present form of að muna.

So the pattern is:

• ég man = I remember
• þú manst = you remember
• hún man = she remembers

A learner often expects something closer to munar, but að muna is irregular in the present tense.

Because Icelandic often uses a hyphen when a foreign abbreviation or acronym is the first part of a compound.

So:

• PIN
  • númer = PIN-númer
• PIN-númer
  • definite article -ið = PIN-númerið

The hyphen helps show the structure clearly. This is very common with imported abbreviations.

It is the direct object of að muna, so it is in the accusative.

However, with many neuter singular nouns, the nominative and accusative look the same. So even though it is accusative here, the form is still PIN-númerið.

That means:

• subject form: PIN-númerið
• object form: PIN-númerið

Same spelling, different function.

Because Icelandic uses the reflexive possessive sinn / sín / sitt when the possessor is the same as the subject of the clause.

Here, the subject is hún, and the PIN number belongs to that same person. So Icelandic uses sitt.

• Hún man PIN-númerið sitt = she remembers her own PIN number

If you used hennar, it would usually suggest someone else’s PIN number, or at least create a non-reflexive reading.

Because sinn / sín / sitt agrees with the thing possessed, not with the owner.

The possessed noun here is PIN-númerið, which is:

• neuter
• singular
• accusative

So the correct form is sitt.

Compare:

• lykillinn sinn = his/her own key
• töskuna sína = his/her own bag
• PIN-númerið sitt = his/her own PIN number

Icelandic adverb placement is fairly flexible, and word order often affects emphasis.

In this sentence, putting alltaf after PIN-númerið sitt gives extra weight to alltaf. It can feel a bit like emphasizing always.

You could also hear:

• Hún man alltaf PIN-númerið sitt

That is also grammatical. The given version makes alltaf slightly more prominent.

They do similar jobs, but not exactly the same one.

• en is the coordinating conjunction: but
• samt means still / nevertheless / all the same

So together they give a stronger contrast:

• en samt = but still / but nevertheless

It is very natural Icelandic, not redundant.

Because Icelandic strongly prefers writing compounds as a single word.

kortalesarinn is built from:

• kort = card
• lesari = reader
• -inn = the definite article

So the whole word means the card reader.

This is extremely typical in Icelandic. English often writes these ideas as two words, but Icelandic usually packs them together.

The -a- is a linking element that appears in many Icelandic compounds. Historically it often comes from an old genitive form, and in modern Icelandic it is simply part of how many compounds are built.

So kortalesari is the normal established compound for card reader.

The important point for learners is: you often have to learn compounds as whole vocabulary items, because the linking vowel is not always predictable from English.

virkar is the 3rd person singular present of að virka, meaning to work, function, operate.

illa is an adverb meaning badly / poorly.

So Icelandic uses:

• verb + adverb
• virkar illa

not an adjective. In other words, Icelandic says the machine functions badly, not that it is bad.

Because Icelandic main clauses normally follow the verb-second principle.

In this clause:

• kortalesarinn = subject
• virkar = finite verb

The finite verb comes early in the clause, in the normal main-clause position. After that, the adverbs are added.

The order here is natural because:

• samt gives the contrast: nevertheless
• stundum gives frequency: sometimes
• illa tells how it works: badly

Other orders are sometimes possible for emphasis, but this one is very standard and natural.