Learn Hardcore Norwegian: Hver av lærerne har sin egen ordbok, men de fleste av elevene bruker bare mobilen. - Each of the teachers has their own dictionary, but most of the pupils use only the mobile phone.

Hver av lærerne har … literally: Each of the teachers has …
In both Norwegian and English, hver / each makes the subject logically and grammatically singular.
So you must use singular verb: hver … har, not hver … har*.

If you removed hver av, then you would say:

Lærerne har sine egne ordbøker. – The teachers have their own dictionaries. (plural subject, plural verb is still har, but other words change: sine egne ordbøker)

Why is it hver av lærerne and not just hver lærer?

Both are possible, but they are not identical:

Hver lærer har sin egen ordbok.
– Refers to teachers in general, or to a group that you have in mind but haven’t mentioned yet.
Hver av lærerne har sin egen ordbok.
– Refers to a specific, known group of teachers (e.g. “the teachers we’re talking about right now”).
– Pattern: hver av + definite plural = each of the …

So hver av lærerne = each of the (specific) teachers.

Why is lærerne in the definite plural form?

Because of the construction hver av + [group]:

With hver av, you almost always use definite plural to show it’s a known, delimited group:
- hver av lærerne – each of the teachers
- hver av studentene
- hver av bøkene

If you said hver lærer, you wouldn’t use av, and you’d use the indefinite singular:

hver lærer – each teacher (in general; not “each of the teachers”)

What is the function of av in hver av lærerne and de fleste av elevene?

Av here marks that we are taking a subset out of a specific group.

hver av lærerne – each of the teachers
de fleste av elevene – most of the students

This is similar to English of.
Structure: [quantifier] + av + [definite plural group]

Why is it sin egen ordbok and not hans egen ordbok or hennes egen ordbok?

Sin is the reflexive possessive pronoun. It refers back to the subject of the clause.

Hver av lærerne har sin egen ordbok.
– sin = “his/her/their own”, referring back to hver av lærerne.

If you used hans or hennes, it would refer to some other person, not the subject:

Hver av lærerne har hans egen ordbok.
– Sounds like: Each of the teachers has *his (some other man’s) own dictionary.*
This is usually wrong in this context.

So: use sin / sitt / sine when the possessor is the subject of the clause.

Why is it sin egen ordbok and not sitt eget ordbok?

Because ordbok is a common gender (en) noun, not neuter.

en ordbok (or ei ordbok) – common (or feminine) gender
The matching forms are:
- sin (common/feminine singular)
- egen (common singular)

For neuter nouns, you would use:

sitt eget hus – his/her own house
(hus is neuter: et hus)

So: sin egen ordbok is correct since ordbok is common gender.

What is the nuance of egen in sin egen ordbok? Could we just say sin ordbok?

Egen adds the meaning “own”, emphasizing that it belongs personally to that teacher.

sin ordbok – their dictionary
sin egen ordbok – their own dictionary (as opposed to a shared one, a school dictionary, etc.)

Without egen, the sentence is still grammatical, but slightly less emphatic:

Hver av lærerne har sin ordbok. – fine, just a bit flatter in meaning.
Hver av lærerne har sin egen ordbok. – highlights personal ownership.

Why is it de fleste av elevene and not just fleste av elevene?

In this meaning, fleste almost always appears with de:

de fleste = most (of them)
fleste alone is rare and usually part of other fixed patterns (e.g. for det meste = for the most part).

So the natural phrase is:

de fleste av elevene – most of the students.

Similarly:

de fleste bøkene / de fleste av bøkene – most of the books.

What is the difference between de fleste av elevene and de fleste elever?

They differ in how specific the group is:

de fleste av elevene
– most of the students in a specific, known group
– e.g. the students in a particular class or school you’re talking about.
de fleste elever
– most students (more general, like “most students in general, typically”)

In this sentence you’re clearly talking about a specific set of students, so de fleste av elevene fits best.

Why is it bruker bare mobilen and not bare bruker mobilen?

Bare here is an adverb meaning only / just. In neutral word order:

The finite verb (bruker) usually comes in second position.
Adverbs like bare typically come after the verb in a main clause:
- De fleste av elevene bruker bare mobilen.

If you say bare bruker mobilen, you would need something in front of it to keep the verb in second position:

Da bare bruker elevene mobilen. – Then the students only use the phone.
(Here da is first, bruker is second.)

So in the original sentence, bruker bare mobilen is the normal, neutral order.

Could we say bruker mobilen bare at the end of the sentence?

You can, but it sounds marked and usually changes the focus:

De fleste av elevene bruker mobilen bare.
– This sounds odd and incomplete, as if something is missing (“use the phone only … (for what?)”).
– Bare at the very end often wants a complement: bare til å … (only to …).

For “just use the phone (instead of a dictionary)”, Norwegians strongly prefer:

bruker bare mobilen.

Why is it mobilen (definite form) and not just mobil?

Norwegian often uses a definite singular form to talk about a type of object in a generic but concrete way:

De fleste av elevene bruker bare mobilen.
– Literally: use just *the mobile (phone)
– Meaning: *use their phone / use the phone (as a tool).

This is natural idiomatic Norwegian, where English tends to use either no article or a possessive:

Norwegian: Han leser avisen. – He reads the newspaper.
English: He reads the newspaper / He reads the paper.

Similarly, mobilen here means “their phone” in context, even though no possessive is said.

Why is there no possessive (like mobilen sin) for “their phone”?

Norwegian often omits possessives when ownership is obvious or not important:

Han har jakken på. – He is wearing (his) jacket.
Hun løfter hånden. – She raises (her) hand.

Here it’s clear that the students use their own phones, so you don’t need to say mobilen sin.

You could say:

… bruker bare mobilen sin.

This is also grammatical and emphasizes that it’s their own mobile, but in everyday speech it’s usually unnecessary; mobilen alone is enough.

Does mobilen mean specifically “mobile phone”, and is this colloquial?

Yes:

en mobil / mobilen – everyday, colloquial word for “mobile phone / cell phone”.
A more formal or explicit term is mobiltelefon.

In ordinary speech and informal writing, mobil is by far the most common. In this sentence, mobilen is natural and idiomatic.