Han prøver å snike seg hjem.

This is very common in Norwegian.

• prøver is the finite verb: it shows tense and agrees with the sentence structure.
• å snike is an infinitive phrase: to sneak.

So the pattern is:

• Han prøver å ... = He tries to ...

Only prøver is conjugated here. snike stays in the infinitive because it comes after å.

A similar example:

• Hun liker å lese. = She likes to read.

Å is the infinitive marker, like English to before a verb.

So:

• å snike = to sneak
• å spise = to eat
• å gå = to go

In Han prøver å snike seg hjem, å links prøver to the action he is trying to do.

Because snike seg is a very common reflexive expression meaning something like sneak away / sneak off / sneak oneself somewhere.

Here, seg shows that the subject is the one doing the sneaking movement.

So:

• Han sniker seg hjem. = He sneaks home.
• Hun snek seg ut. = She sneaked out.

If you remove seg, the sentence sounds unnatural or changes meaning. In this kind of movement expression, snike seg is the normal form.

Seg is a reflexive pronoun. It refers back to the subject.

In this sentence:

• Han = he
• seg = himself

So Han prøver å snike seg hjem literally contains the idea He tries to sneak himself home, although in natural English we just say He tries to sneak home.

Norwegian uses reflexive pronouns more often than English in some verbs and expressions.

Because the action refers back to the subject.

• seg = reflexive, referring back to han
• ham = regular object pronoun, meaning him

So:

• Han prøver å snike seg hjem. = He is the one sneaking.
• Han prøver å snike ham hjem. would mean he is trying to sneak another male person home, which is a very different idea and sounds unusual.

When the object refers back to the subject, Norwegian normally uses the reflexive form.

Because hjem can work on its own to mean homeward / home after a verb of movement.

So Norwegian often says:

• gå hjem = go home
• komme hjem = come home
• kjøre hjem = drive home
• snike seg hjem = sneak home

English does the same in many cases: we say go home, not go to home.

This is a very common learner question.

• hjem usually shows movement toward home
• hjemme usually shows location at home

Examples:

• Han drar hjem. = He is going home.
• Han er hjemme. = He is at home.

So in your sentence, hjem is used because he is trying to get to that place.

Because in a normal Norwegian main clause, the usual order is:

• subject + finite verb + rest

Here that gives:

• Han = subject
• prøver = finite verb
• å snike seg hjem = the rest of the verb phrase

So the structure is very straightforward.

If you start with another element, Norwegian usually puts the finite verb second:

• I kveld prøver han å snike seg hjem.

That is the famous verb-second pattern in Norwegian main clauses.

Snike suggests moving quietly, secretly, or without wanting to be noticed.

So snike seg hjem can suggest things like:

• trying not to wake anyone
• trying not to be seen
• slipping home quietly
• sneaking back home after being out

It often carries a slightly secretive or guilty feeling, depending on context.

The reflexive pronoun changes with 1st and 2nd person, but seg is used for 3rd person.

Examples:

• Jeg prøver å snike meg hjem. = I try to sneak home.
• Du prøver å snike deg hjem. = You try to sneak home.
• Han prøver å snike seg hjem. = He tries to sneak home.
• Hun prøver å snike seg hjem. = She tries to sneak home.
• De prøver å snike seg hjem. = They try to sneak home.

So seg is specifically the reflexive form used with han, hun, and de.

You change the finite verb prøver to the past tense:

• Han prøvde å snike seg hjem. = He tried to sneak home.

You can also make a present perfect version:

• Han har prøvd å snike seg hjem. = He has tried to sneak home.

Notice that snike stays in the infinitive after å. Only the first verb changes form.