Avledningen begynner snart.

In Norwegian, the definite article is usually added to the end of the noun.

• en/ei avledning = an/a ...
• avledningen / avledninga = the ...

So English uses a separate word the, but Norwegian normally uses a noun ending for that job.

Yes. In Bokmål, avledning can be treated as a feminine noun, so you may see:

• ei avledning → avledninga

But Bokmål also often allows feminine nouns to use the common-gender/masculine pattern:

• en avledning → avledningen

So avledningen is normal, and avledninga may also be correct depending on style and preference.

Begynner is the present tense of å begynne.

Examples:

• jeg begynner
• du begynner
• han/hun begynner
• vi begynner

Unlike English, Norwegian verbs do not change according to the subject. The same present-tense form is used for all persons.

Norwegian very often uses the present tense for planned, expected, or near-future events, especially when there is a time word like snart.

So Avledningen begynner snart is completely natural. English can do something similar too in sentences like The show starts soon.

If you want, Norwegian can also express the future more explicitly, for example:

• Avledningen skal snart begynne
• Avledningen kommer til å begynne snart

But the simple present is very common here.

Snart means soon. It tells you the action will happen after a short time.

In this sentence, it works as an adverb modifying begynner. It does not have to mean an exact number of minutes; it just means before long or in a little while.

That is a very normal word order in Norwegian:

• Avledningen begynner snart.

The adverb often comes after the verb in a simple main clause like this.

But you can move snart to the front for emphasis:

• Snart begynner avledningen.

When that happens, Norwegian still keeps the verb in second position, so begynner comes before avledningen.

Often yes, depending on the context.

• begynne = begin
• starte = start

In many everyday situations, both work. Begynne is very general and neutral. Starte is also common, and can sometimes sound a bit more like the beginning of an event, process, or activity.

So Avledningen starter snart may also be possible, but begynner is a very safe and natural choice.

Yes, this is standard Bokmål.

A Nynorsk version would often look different, both in spelling and sometimes in word choice. So if you are learning Bokmål, this sentence is perfectly normal as written.