Het expertiserapport omschrijft de oorzaak.

Dutch nouns take one of two definite articles:

• de for common-gender words
• het for neuter words

In this sentence:

• rapport is a het-word, so expertiserapport is also a het-word
• oorzaak is a de-word

A useful rule for compound nouns is that the article is usually determined by the last part of the compound. Since the last part is rapport, you get het expertiserapport.

So:

• het rapport
• het expertiserapport
• de oorzaak

Expertiserapport is a compound noun:

• expertise = expert assessment, professional evaluation
• rapport = report

Together, expertiserapport means something like:

• expert report
• assessment report
• inspection report

The exact English translation depends on context. In insurance, legal, or technical contexts, it often refers to a report written by a specialist after examining a situation.

Omschrijven is the infinitive, meaning to describe or to define.

In the sentence, the subject is singular:

• Het expertiserapport = the expert report

So the verb must be in the third person singular present tense:

• ik omschrijf
• jij omschrijft / omschrijft
• hij/zij/het omschrijft
• wij omschrijven
• jullie omschrijven
• zij omschrijven

Because the subject is singular, Dutch uses omschrijft.

They are similar, but not always identical.

• beschrijven = to describe
• omschrijven = to describe, define, or characterize, often in a slightly more precise or formal way

In this sentence, omschrijft de oorzaak suggests that the report sets out, defines, or describes the cause.

So a natural English idea is:

• The report describes the cause
• The report outlines the cause
• The report identifies and describes the cause

In many contexts, beschrijft could also work, but omschrijft can sound a bit more formal or exact.

This is standard Dutch main-clause word order:

• subject
  • finite verb
    • rest of the sentence

So:

• Het expertiserapport = subject
• omschrijft = finite verb
• de oorzaak = object

Dutch is a verb-second language in main clauses. That means the finite verb usually comes in the second position.

Here, the subject is first, so the verb comes right after it:

• Het expertiserapport omschrijft de oorzaak.

If you move another element to the front, the verb still stays second:

• De oorzaak omschrijft het expertiserapport.
  This is grammatically possible, but now it sounds like the cause describes the report, so the meaning changes.

Or with an adverb:

• Vandaag omschrijft het expertiserapport de oorzaak.

So the sentence follows the normal Dutch pattern.

Because de oorzaak is the direct object, and in a simple Dutch main clause, the direct object often comes after the finite verb.

Structure:

• Het expertiserapport = subject
• omschrijft = verb
• de oorzaak = direct object

This is very similar to English:

• The expert report / describes / the cause

So for an English speaker, this sentence is actually quite straightforward in word order.

Yes. De oorzaak means the cause, not just a cause or cause in general.

Dutch usually needs an article before a singular countable noun, just like English does.

Compare:

• de oorzaak = the cause
• een oorzaak = a cause

Using no article here would usually be incorrect in a normal sentence like this.

So de oorzaak suggests a specific cause that is already known from context or is being identified as a particular one.

A rough guide:

• om sounds like om in tom but shorter
• schr is a tricky Dutch cluster; sch is often like a hard throaty sound, and then r
• ij sounds somewhat like ei in some Dutch words, but English speakers often learn it approximately like the vowel in eye
• final ft is pronounced clearly

Very roughly, you could think of it as something like:

• OM-skhreift

But that is only approximate. The hardest parts for English speakers are usually:

• the Dutch sch
• the diphthong ij
• saying the final consonants clearly

Because Dutch usually writes compound nouns as one word.

So where English often writes:

• expert report
• insurance report
• damage report

Dutch often combines them:

• expertiserapport
• verzekeringsrapport
• schaderapport

This is extremely common in Dutch. Long words are normal, and they are often just smaller nouns joined together.

Yes, in many contexts that would be natural and grammatical.

The difference is mainly nuance:

• beschrijft = describes
• omschrijft = describes/defines/outlines more precisely

Depending on context, both may be possible. If the report is formally stating or characterizing the cause, omschrijft may sound especially appropriate.

So:

• Het expertiserapport beschrijft de oorzaak.
• Het expertiserapport omschrijft de oorzaak.

Both can work, but omschrijft may feel a little more formal or exact.

Yes, definitely. The sentence sounds fairly formal and professional because of the vocabulary:

• expertiserapport is technical or administrative
• omschrijft is slightly formal in tone

This sounds like something you might see in:

• an insurance document
• a legal report
• a technical inspection
• an official assessment

In everyday casual speech, people might choose simpler wording depending on the context.