På vei hjem kjøper jeg yoghurt og epler.

Because Norwegian main clauses normally follow the V2 rule: the finite verb must be in the second position.

Here, På vei hjem comes first, so that takes position 1. The verb kjøper must then come in position 2, and the subject jeg comes after it.

• På vei hjem kjøper jeg yoghurt og epler.
• Jeg kjøper yoghurt og epler på vei hjem.

Both are correct, but the first one gives extra emphasis to on the way home.

It is a very common expression meaning on the way home.

• på vei = on the way
• hjem = home / homeward

So på vei hjem is not a word-for-word English structure, but it is a natural Norwegian phrase used when someone is traveling back home.

It does not mean only walking; it can refer to going home by car, bus, train, bike, or on foot.

Because hjem usually expresses direction or movement, while hjemme expresses location.

• Jeg drar hjem. = I am going home.
• Jeg er hjemme. = I am at home.

In På vei hjem, the idea is movement toward home, so hjem is the correct choice.

Yes. That is also correct.

The difference is mainly emphasis:

• På vei hjem kjøper jeg yoghurt og epler.
  Emphasizes when / under what circumstances you buy them.
• Jeg kjøper yoghurt og epler på vei hjem.
  Sounds a bit more neutral to an English speaker, because it starts with the subject.

Both are natural Norwegian.

Because Norwegian often leaves out an article where English would use some or no article at all.

• yoghurt here is being used like a mass noun, similar to milk or bread
• epler is an indefinite plural, meaning apples in a general sense

So:

• kjøper yoghurt = buy yogurt
• kjøper epler = buy apples

If you wanted to be more specific, you could add words like:

• en yoghurt = one yogurt
• noen epler = some apples

The singular form is eple.

• et eple = an apple
• eplet = the apple
• epler = apples
• eplene = the apples

So in the sentence, epler is simply the indefinite plural form.

Norwegian uses the present tense in several ways, just like English sometimes does.

In this sentence, kjøper could mean:

• a habitual action: I buy yogurt and apples on the way home
• a present-time description
• sometimes even a near-future action, depending on context

Without more context, it often sounds like a general or habitual statement.

No. It is an adverbial phrase, not a full clause.

There is no subject and no finite verb inside på vei hjem. It functions like a time/circumstance expression at the beginning of the sentence, telling you when or under what circumstances the action happens.

The full clause is:

kjøper jeg yoghurt og epler

And på vei hjem modifies that clause.

Usually it sounds general or uncountable here, like some yogurt.

If you mean one specific yogurt cup, Norwegians would often say:

• en yoghurt

So:

• Jeg kjøper yoghurt. = I buy yogurt / some yogurt
• Jeg kjøper en yoghurt. = I buy a yogurt

The version in your sentence sounds broader and less specific.

Yes, very natural.

It sounds like normal spoken or written Bokmål. The structure with a fronted phrase, followed by the verb, is extremely common in Norwegian, and the vocabulary is everyday vocabulary.