Learn Hardcore Norwegian: Deres forhold virker sterkt, men følelsene hans er noen ganger uklare. - Their relationship seems strong, but his feelings are sometimes unclear.

their – possession by some third-person group:
- Deres forhold virker sterkt = Their relationship seems strong.
Formal your – polite form of your (singular or plural), traditionally written with capital D:
- Deres bil står der borte. = Your car is over there. (very polite/formal)

In this sentence, because it’s at the beginning, Deres/deres is automatically capitalized, so you need context to know if it means their or formal your.
In modern spoken Norwegian, the formal Deres is quite rare outside letters and very formal situations, so in everyday language this will usually be understood as their.

Why is forhold used for relationship? Doesn’t it also mean condition/situation?

Yes, forhold is a very flexible word. Common meanings include:

relationship (between people):
- et kjærlighetsforhold – a romantic relationship
- Deres forhold virker sterkt – Their relationship seems strong
conditions / circumstances / situation:
- arbeidsforhold – working conditions
- under vanskelige forhold – under difficult circumstances
ratio in math:
- forholdet mellom 2 og 4 – the ratio between 2 and 4

In this sentence, context (mentioning følelsene hans – his feelings) makes it clear that forhold means a romantic/close relationship.

Why is it virker sterkt and not something like ser sterkt ut or er sterkt?

Norwegian has several verbs that can be translated as seem / look / appear:

virke – to seem, to appear (also to work/function in other contexts)
se ... ut – to look (appear)
fremstå – to appear, to come across as

Virke here is used in its “seem/appear” meaning:

forholdet deres virker sterkt = their relationship seems strong

Could you use other options?

forholdet deres ser sterkt ut – also possible and natural; focuses slightly more on outward impression.
forholdet deres er sterkt – a stronger, more factual statement: their relationship is strong, not just seems.

So virker is chosen to keep it a bit subjective: it appears strong.

Why is it sterkt and not sterk or sterke?

Adjectives in Norwegian agree with the gender and number of the noun:

forhold is a neuter noun: et forhold (a relationship)
Predicate adjectives (after verbs like er, virker, blir) also agree with the noun:
- et forhold er sterkt – a relationship is strong

Summary:

sterk – masculine/feminine singular (e.g. en sterk mann)
sterkt – neuter singular (e.g. et sterkt forhold)
sterke – plural (e.g. sterke forhold)

Since forhold is neuter singular, the correct form here is sterkt.

Why is it følelsene hans and not hans følelser?

Both are grammatically correct, but they’re used a bit differently.

følelsene hans – the most common, neutral way to say his feelings:
- definite noun (følelsene = the feelings) + possessive after it (hans)
hans følelser – also possible, but this word order often adds emphasis to the owner:
- hans følelser = his feelings (as opposed to someone else’s)

So:

følelsene hans er noen ganger uklare – neutral, everyday way.
hans følelser er noen ganger uklare – sounds a bit more marked, like you are stressing that man’s feelings in contrast to others.

In practice, for his/her/their + definite noun, the pattern [definite noun] + hans/hennes/deres is the most typical everyday choice.

Why can’t we use sine instead of hans here?

Norwegian distinguishes between reflexive and non‑reflexive possessives:

sin / si / sitt / sine – reflexive (one’s own), referring back to the subject of the clause.
hans / hennes / deres – non‑reflexive, referring to someone else.

The subject of the sentence is Deres forhold (their relationship). If we said:

Deres forhold virker sterkt, men følelsene sine er noen ganger uklare.

then sine would refer back to Deres forhold (the relationship), which makes no sense – a relationship doesn’t have its own feelings.

We want to talk about his feelings (some specific man), different from the subject Deres forhold, so we must use hans, not sine.

Why is it noen ganger and not noe ganger or something else?

noen = some / a few (for countable things, plural)
ganger = plural of gang = time/occasion

So noen ganger literally means some times / a few times, i.e. sometimes.

You can’t use noe ganger here because:

noe is used with uncountable nouns or as a general “something / anything”:
- noe vann – some water
- noe interessant – something interesting

Other common ways to say sometimes:

av og til
innimellom
sommetider (a bit old-fashioned or literary)

All of these could replace noen ganger with almost the same meaning:

… men følelsene hans er av og til uklare.

Why is the word order følelsene hans er noen ganger uklare and not er uklare noen ganger?

Both are possible, but they sound a bit different:

følelsene hans er noen ganger uklare – adverb (noen ganger) is placed in the middle field, which is the most natural and neutral placement.
følelsene hans er uklare noen ganger – also correct, but noen ganger at the end can sound a little more afterthought-like or slightly more informal/emphatic.

General rule: in main clauses, adverbs like ofte, alltid, noen ganger usually go after the verb (here er) and before the adjective:

De er ofte trøtte.
Han er noen ganger stille.
Følelsene hans er noen ganger uklare.

Why is it uklare and not uklar or uklart?

The adjective uklar (unclear) has these forms:

uklar – masculine/feminine singular
uklart – neuter singular
uklare – plural (and also used before definite nouns with de)

Here the noun is følelsene = the feelings, which is plural:

én følelse – one feeling
flere følelser – several feelings
følelsene – the feelings (definite plural)

Predicate adjectives with plural nouns take the plural form:

følelsene er uklare – the feelings are unclear
tankene er uklare – the thoughts are unclear

So uklare is correct because følelsene is plural.

Can this sentence also be Forholdet deres virker sterkt, men noen ganger er følelsene hans uklare? Is there any difference?

Yes, that alternative is perfectly correct:

Forholdet deres virker sterkt, men noen ganger er følelsene hans uklare.

Differences:

Deres forhold vs Forholdet deres:
- Both mean their relationship.
- Forholdet deres (definite noun + possessive after) is often the most natural everyday pattern.
- Deres forhold (possessive before) is also fine, sometimes a bit more formal or written-style.
noen ganger er følelsene hans uklare vs følelsene hans er noen ganger uklare:
- Both are grammatical and natural.
- Starting the clause with noen ganger puts extra focus on the frequency:
  - Sometimes, his feelings are unclear…
- Keeping følelsene hans first is a bit more neutral.

So your alternative is good Norwegian, just with a slightly different rhythm and emphasis.