Skjólstæðingurinn hvílir sig.

It is made of:

• skjólstæðingur = client, patient, ward, or someone under another person’s care/protection, depending on context
• -inn = the (the definite article attached to the noun)

So skjólstæðingurinn means the client/patient/ward.

A useful thing to notice is that Icelandic usually adds the to the end of the noun instead of using a separate word like English does.

That is a normal feature of Icelandic. The definite article is often a suffix.

So instead of:

• English: the client

you often get:

• Icelandic: skjólstæðingur = client
• skjólstæðingurinn = the client

This attached article changes form depending on the noun’s gender, number, and case.

Because hvílir is the form that agrees with a third-person singular subject.

The subject here is Skjólstæðingurinn = the client/patient, which is singular, so the verb must also be singular.

The verb is hvíla in the dictionary form (infinitive), but in the present tense it changes:

• ég hvíli = I rest
• þú hvílir = you rest
• hann/hún/það hvílir = he/she/it rests

So:

• Skjólstæðingurinn hvílir = The client rests

Sig is a reflexive pronoun. It means something like himself / herself / itself / themselves, depending on the context.

In this sentence, hvíla sig means to rest oneself, which is the normal Icelandic way to say rest in many contexts.

So:

• hvíla sig = to rest
• literally: to rest oneself

That is why the sentence includes sig. English usually just says rests, but Icelandic often uses the reflexive pronoun here.

No. Sig is specifically reflexive, which means it refers back to the subject of the same clause.

Compare:

• Hann hvílir sig. = He rests / He is resting.
  Here sig refers back to hann.

But if you used a non-reflexive object pronoun, it would mean someone else:

• Hann sér hann. = He sees him.
  Usually this means he sees another male person, not himself.

So in your sentence, sig shows that the resting is done by the subject to themself.

Here sig is in the accusative case.

That is because the verb expression hvíla sig takes a direct object in the accusative. Even though English does not show this clearly, Icelandic does.

So the structure is:

• Skjólstæðingurinn = subject, nominative
• hvílir = verb
• sig = reflexive object, accusative

This is very common in Icelandic: many verbs require a certain case for their object.

Skjólstæðingur is a masculine noun.

Yes, that matters, because gender affects:

• the form of the definite article
• adjective agreement
• pronoun reference
• declension patterns

That is why the definite form is skjólstæðingurinn rather than a feminine or neuter form.

Even if the real-world person could be of any gender depending on context, the noun itself is grammatically masculine.

A rough guide for an English speaker:

• Skjólstæðingurinn ≈ SKYOHL-stai-thing-ur-inn
• hvílir ≈ KVEE-lir
• sig ≈ sihgh or sig with a soft Icelandic g

A few pronunciation notes:

• skj at the start is not like English sk. It is more like a soft sky sound.
• ó is a long vowel, roughly like oh.
• æ is like eye.
• hv in modern Icelandic is usually pronounced like kv.
• í sounds like ee.
• final -ur is often lightly pronounced.

Pronunciation varies a little by speaker, but those approximations will get you close.

Yes. Very often, the Icelandic present tense can cover both:

• The client rests
• The client is resting

Context usually tells you which one is more natural in English.

If Icelandic wants to be especially explicit about an ongoing action, it can use other constructions, but the simple present is very commonly used where English would prefer the present continuous.

Sometimes hvíla can appear without sig, but hvíla sig is the common everyday way to express resting oneself.

So for a learner, it is best to treat:

• hvíla sig as a standard expression

If you leave out sig, the meaning may shift depending on context, and it may sound less natural in cases where English simply says rest.

Because this is a plain declarative main clause, and that is a normal basic order in Icelandic.

So:

• Skjólstæðingurinn = subject
• hvílir = verb
• sig = object

Icelandic also has verb-second word order, which means the finite verb is often in the second position of the clause. In a simple sentence like this, that gives you straightforward subject–verb–object order.

For example, if you begin with another element, the verb still tends to stay second:

• Núna hvílir skjólstæðingurinn sig. = Now the client is resting.

The dictionary forms are:

• skjólstæðingur → the noun
• hvíla (sig) → the verb/expression
• sig → the reflexive pronoun

It is often useful to learn the verb here as hvíla sig, not just hvíla, because that is how it is commonly used for the meaning to rest.

It is a real and useful word, but it is somewhat context-specific. You are especially likely to see it in:

• healthcare
• therapy
• social work
• legal or support services
• professional/care relationships

Depending on context, English translations might include:

• client
• patient
• person under care
• ward

So it is not quite as broad and everyday as a word like maður (person/man) or sjúklingur (patient), but it is common in the right settings.