Hún losar skrúfuna.

Because hún is the subject form, called the nominative. In this sentence, she is the one doing the action, so Icelandic uses hún.

hana is the object form, called the accusative, and would be used if her were receiving the action instead.

So:

• hún = she
• hana = her

Yes.

When it refers to a female person, hún means she. But Icelandic also uses hún for nouns that are grammatically feminine, even if they are inanimate, in which case it can be translated as it.

So hún is not only about biological sex; it can also reflect grammatical gender.

Losar is the present tense, 3rd person singular form of the verb losa.

That means it matches subjects like:

• hann = he
• hún = she
• það = it

So:

• ég losa = I loosen
• þú losar = you loosen
• hún losar = she loosens

In context, Icelandic present tense can often correspond to either English she loosens or she is loosening.

Because skrúfuna is not the basic dictionary form. It is the definite accusative singular form.

The dictionary form is skrúfa, which is like screw as a basic noun form. But in the sentence, the noun is:

• definite = the screw
• direct object
• therefore in the accusative

So the form changes to skrúfuna.

A helpful mini-paradigm is:

• skrúfa = a screw / screw, nominative
• skrúfan = the screw, nominative
• skrúfu = a screw, accusative
• skrúfuna = the screw, accusative

In Icelandic, the is usually attached to the end of the noun instead of being written as a separate word.

So skrúfuna already includes the.

You can think of it roughly like this:

• skrúfu = screw
• skrúfuna = the screw

The exact ending changes depending on the noun's gender, number, and case.

Because it is the direct object of the verb losar.

The direct object is the thing affected by the action. Here, the action is being done to the screw, so Icelandic puts skrúfuna in the accusative.

This is very common in Icelandic: many verbs take an accusative direct object.

Skrúfa is a feminine noun.

Yes, that matters, because in Icelandic a noun's gender affects:

• its endings
• the form of the definite article
• adjective agreement
• pronouns that refer back to it

In this sentence, the main visible effect is in the noun form skrúfuna. If you later referred back to the screw, Icelandic could use a feminine pronoun for it.

This is the most neutral word order: subject + verb + object.

But Icelandic word order is more flexible than English because case endings help show what each word is doing. In main clauses, the finite verb usually stays in second position.

For example:

• Núna losar hún skrúfuna. = Now she loosens the screw.
• Skrúfuna losar hún. = It is the screw that she loosens / The screw, she loosens it.

So the sentence you have is the plain, standard order, but not the only possible one.

A rough English-friendly pronunciation is SKROO-vu-na.

One useful Icelandic pronunciation rule is that f often sounds like v when it appears between vowels or in other voiced environments. So in skrúfuna, many learners hear something closer to skrúvuna.

Also, Icelandic stress normally falls on the first syllable, so:

• HÚN
• LÓ-sar
• SKRÚ-fu-na

Not always. Losa can mean things like:

• loosen
• release
• detach
• undo
• free

The best English translation depends on context. So even if your translation gives one meaning, it is good to remember that the Icelandic verb is a little broader than a single English word.