I opplæringen forklarer kollegaen hennes hver arbeidsoppgave rolig og tydelig.

It is a prepositional phrase that sets the scene or context.

• i = in
• opplæringen = the training / the training period

In this sentence, I opplæringen means something like during the training or in the training process.

Norwegian often puts this kind of time or context phrase first when the speaker wants to highlight it.

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

Here, I opplæringen is placed first. Once that happens, the verb must come next:

• I opplæringen = first position
• forklarer = second position
• kollegaen hennes = subject

So the sentence structure is normal Norwegian:

• I opplæringen forklarer kollegaen hennes ...

If you started with the subject instead, you would get:

• Kollegaen hennes forklarer ...

That is also correct.

Because of the word order and the sentence pattern.

In this sentence:

• forklarer is the finite verb
• kollegaen hennes comes right after the verb and is the person doing the action
• hver arbeidsoppgave is what is being explained

So:

• kollegaen hennes = subject
• hver arbeidsoppgave = direct object

This can feel unusual to an English speaker because English usually keeps the subject before the verb, but Norwegian changes the order when something else is placed first.

That -en is the definite ending, roughly corresponding to English the.

So:

• opplæring = training
• opplæringen = the training

and

• kollega = colleague
• kollegaen = the colleague

Norwegian usually attaches definiteness to the end of the noun instead of putting a separate word like the in front.

Both are possible, but they are not used in exactly the same way.

The most common everyday pattern in Norwegian is:

• noun in definite form + possessive
• kollegaen hennes = her colleague

That is why you see kollegaen in definite form before hennes.

The alternative:

• hennes kollega

is also grammatical, but it often sounds more emphatic, more formal, or more contrastive, as if you are stressing her colleague in particular.

So for neutral everyday Norwegian, kollegaen hennes is the most natural choice.

Because hver means each or every, and in Norwegian it normally takes a singular count noun.

So:

• hver arbeidsoppgave = each work task / each job task

Not:

• hver arbeidsoppgaver

That would be incorrect.

This is similar to English, where we say each task, not each tasks.

Because hver already works as a determiner.

In other words, hver fills the same slot where you might otherwise have an article.

So you say:

• hver arbeidsoppgave

not

• en hver arbeidsoppgave
• hver arbeidsoppgaven

Also notice that after hver, the noun is usually indefinite singular.

Yes. Norwegian very often forms compound nouns by writing them as one word.

Here:

• arbeid = work
• oppgave = task / assignment

Together:

• arbeidsoppgave = work task / job task

This is very common in Norwegian. English often uses two words where Norwegian uses one compound word.

Here they function adverbially: they describe how the explaining is done.

So they tell us the manner of the action:

• rolig = calmly
• tydelig = clearly

In Norwegian, words that are adjectives in other contexts can often be used adverbially like this.

For example:

• en rolig person = a calm person
• hun snakker rolig = she speaks calmly

and

• en tydelig forklaring = a clear explanation
• han forklarer tydelig = he explains clearly

That is a very normal placement for adverbials of manner in Norwegian.

A common pattern is:

• subject + verb + object + manner adverbial

So here:

• kollegaen hennes
• forklarer
• hver arbeidsoppgave
• rolig og tydelig

This is natural Norwegian word order.

If there were no object, the adverbs could come directly after the verb:

• Hun forklarer rolig og tydelig.

But when there is an object, it is very common to place the adverbs after it.

Yes. That is also correct.

The difference is mainly about focus:

• I opplæringen forklarer kollegaen hennes ...
  This emphasizes the training context first.

• Kollegaen hennes forklarer ... i opplæringen
  This is a more neutral subject-first structure.

Both are natural. The first version simply follows a common Norwegian pattern where a time or context phrase is fronted, which then triggers verb-second word order.