Learn Hardcore Norwegian: Han skjuler ikke følelsene sine; han skriver dem som de er, selv om de er personlige. - He does not hide his feelings; he writes them as they are, even though they are personal.

You can say sine følelser, but that sounds more marked or emphatic, and in many contexts a bit more formal or literary. Here, følelsene sine is what you would normally say in everyday language.

Why do we use sine instead of hans for his feelings?

Norwegian distinguishes between:

reflexive possessives: sin / sitt / sine
– used when the possessor is the subject of the same clause
non‑reflexive possessives: hans / hennes / deres, etc.
– used when the possessor is someone else, not the subject

In Han skjuler ikke følelsene sine, the subject is han, and the feelings belong to that same han, so we must use the reflexive:

følelsene sine = his own feelings (the subject’s feelings)

If we said følelsene hans, it would normally suggest the feelings of some other man (not the subject), or at least be ambiguous.

Why is it følelsene (definite plural) and not just følelser (indefinite plural)?

Følelsene is definite plural: the feelings.
Using the definite form here signals a specific, known set: his particular feelings, the ones he has.

If you said Han skjuler ikke følelser, it would mean He doesn’t hide feelings in a very general sense, almost like a character trait about feelings in general.
Han skjuler ikke følelsene sine is more natural for He doesn’t hide his feelings (the ones he actually has).

Why is the negation placed as skjuler ikke, and not ikke skjuler?

In a main clause, Norwegian tends to put the finite verb in second position (V2). Negation ikke usually comes after that verb:

Subject – Verb – ikke – rest
Han skjuler ikke følelsene sine.

If you move something else to the front, the verb is still second, and ikke still follows the verb:

Likevel skjuler han ikke følelsene sine.
(Adverb – Verb – Subject – ikke – rest)

Ikke skjuler han følelsene sine is possible, but it is unusual and has a strong, marked emphasis (“It is not the case that he hides his feelings”), more like stylistic rhetoric.

Why is it dem in han skriver dem, but de in som de er?

Norwegian still distinguishes subject and object forms in plural:

de = subject form (they)
dem = object form (them)

So:

han skriver dem – dem is the object of the verb skriver, so we use the object form.
som de er – de is the subject of the verb er, so we use the subject form.

Both de and dem refer back to følelsene.

Why does personlige end with -e and not just personlig?

Predicate adjectives in Norwegian usually agree with the number and definiteness of the noun they refer to:

en personlig følelse – a personal feeling (singular)
personlige følelser – personal feelings (plural)

In the sentence:

som de er, selv om de er personlige

Here de refers to følelsene (plural), so the adjective must also be plural:

de er personlige (they are personal)

With a singular noun, you would say:

Følelsen er personlig. – The feeling is personal.

What exactly does som de er mean? Is som “which” or “as”?

In this context, som means as, not which:

han skriver dem som de er
≈ he writes them as they are

It expresses that he writes his feelings in their true form, without changing or softening them.
So som here introduces a phrase of manner/comparison: in the way they are.

Could we say Han skriver dem slik de er instead of som de er?

Yes, Han skriver dem slik de er is also correct and natural.

som de er and slik de er here both mean as they are / the way they are.
slik makes the manner slightly more explicit, but the meaning in this sentence is basically the same.

What does selv om mean, and how does it work grammatically?

Selv om is a subordinating conjunction meaning even though / although.

It introduces a subordinate clause with normal subject–verb order (no extra V2 inversion):

selv om de er personlige
= even though they are personal

Structure:

Main clause: Han skjuler ikke følelsene sine; han skriver dem som de er
Subordinate clause: selv om de er personlige

You cannot split it as selv de om er personlige or anything like that; selv om is a fixed two-word unit.

Why is there a semicolon (;) and not just a comma or a period?

Both parts are complete main clauses:

Han skjuler ikke følelsene sine
han skriver dem som de er, selv om de er personlige

A semicolon is used to connect two closely related independent clauses more tightly than a period, but more clearly than a comma.

You could also write:

Han skjuler ikke følelsene sine. Han skriver dem som de er, selv om de er personlige.

That is fully correct. The semicolon is mainly a stylistic choice to show a strong link between the two statements.

What is the difference between skjuler and gjemmer?

Both can mean to hide, but there is a nuance:

skjule: to hide, conceal, cover up (often more abstract: feelings, truth, intentions)
gjemme: to hide, put away somewhere (more often physical objects)

Some typical patterns:

skjule følelsene / sannheten / en hemmelighet
gjemme en nøkkel / en leke / penger

Here, Han skjuler ikke følelsene sine is natural because we are talking about feelings, something abstract that you conceal rather than physically stash away.

Which tense is skjuler and skriver, and why present tense here?

Skjuler and skriver are present tense forms:

infinitive: å skjule, å skrive
present: skjuler, skriver

Norwegian present tense covers:

English simple present: he writes
and often also English present progressive: he is writing, he is hiding

In this sentence, present tense is used to describe a general, habitual characteristic:

Han skjuler ikke følelsene sine; han skriver dem som de er …
≈ He doesn’t (tend to) hide his feelings; he writes them as they are …