Vores nye kollega er grundig og nøjagtig, når hun læser dokumenter.

Because vores already makes the noun phrase definite enough on its own. In Danish, a possessive usually replaces an article, so you say vores nye kollega, not en vores nye kollega or vores nye kollegaen.

This is the same pattern as:

• min bil
• hans søster
• deres hus

So the structure possessive + adjective + noun is completely normal here.

This is because Danish adjectives behave differently depending on where they appear.

Before the noun, ny is an attributive adjective, and after a possessive like vores, it normally takes the -e form:

• vores nye kollega
• min gamle ven

After er, grundig and nøjagtig are predicative adjectives. Predicative adjectives do not take the definite -e just because the subject is definite. Instead, they agree mainly with gender and number:

• Kollegaen er grundig
• Huset er grundigt
• Kollegaerne er grundige

So nye is correct before the noun, while grundig and nøjagtig are correct after er.

Kollega is a common-gender noun: en kollega. That matters because singular common-gender nouns usually use the basic adjective form in predicative position:

• kollegaen er grundig

If it were a neuter noun, you would often see -t on the adjective:

• arbejdet er grundigt

So in your sentence, grundig and nøjagtig match the singular common-gender subject kollega.

Usually, no. Vores is the normal modern form for our, and it does not change for singular/plural or common/neuter nouns:

• vores kollega
• vores hus
• vores dokumenter

You may sometimes meet older or more literary forms like vor, vort, and vore, but in everyday modern Danish, vores is the standard choice.

They are similar, but not identical.

• grundig means thorough, careful in covering everything
• nøjagtig means accurate, precise, or very exact

So together they give a stronger description: she is not only careful and complete, but also precise. A person can be grundig without being especially exact, and nøjagtig without necessarily being broad or comprehensive. Using both sounds natural here.

The sentence describes a general characteristic and a habitual situation, so the present tense is natural. It means this is the kind of person she is, and this is how she behaves when she reads documents.

Danish often uses the present tense in exactly this way, much like English:

• Hun er grundig
• Hun læser dokumenter omhyggeligt
• Når hun læser dokumenter, ...

So the sentence is not about one single event, but about a repeated or typical pattern.

Når is used for when in a general, repeated, or habitual sense: whenever / when she reads documents.

That fits this sentence well, because it is talking about her usual behavior.

Compare:

• når = when/whenever, in general or in the future
• da = when, for one specific event in the past
• mens = while, emphasizing that two things happen at the same time

So:

• når hun læser dokumenter = whenever she reads documents
• da hun læste dokumenterne = when she read the documents (one past occasion)
• mens hun læser dokumenter = while she is reading documents

Because når hun læser dokumenter is a subordinate clause. Danish main clauses usually follow the verb-second rule, but subordinate clauses do not.

So in the main clause you get:

• Vores nye kollega er grundig og nøjagtig

But after når, the normal order is:

• når + subject + verb
• når hun læser dokumenter

If there were an adverb like ikke, it would also show typical subordinate-clause order:

• når hun ikke læser dokumenter

That is a very useful pattern to notice.

Because many Danish writers use a comma before a subordinate clause. Here, når hun læser dokumenter is a subordinate clause.

However, there is an important detail: modern Danish allows two comma systems. In the start comma system, you write the comma before the subordinate clause. In the no-start comma system, you do not.

So both of these can be acceptable, depending on the system being used:

• Vores nye kollega er grundig og nøjagtig, når hun læser dokumenter.
• Vores nye kollega er grundig og nøjagtig når hun læser dokumenter.

The version with the comma is very common.

Because the sentence is talking about documents in general, not a specific set of documents already known to the listener.

• dokumenter = documents, in general
• dokumenterne = the documents, a specific group

So når hun læser dokumenter means when she reads documents as part of her work or in general. If you meant particular documents, you would say:

• når hun læser dokumenterne

In this sentence, they describe the person: vores nye kollega. Grammatically, they are linked to the subject through er.

So the meaning is closer to our new colleague is a thorough and accurate person when she reads documents, not directly she reads documents thoroughly and accurately.

If you wanted to describe the action more directly, you would usually change the structure, for example:

• Hun læser dokumenter grundigt og nøjagtigt.

That version focuses more on how she reads. The original sentence focuses more on what kind of colleague she is in that situation.

No, not in standard Danish. After a possessive like vores, the adjective before the noun normally takes the -e form, so it must be:

• vores nye kollega

The form ny would be used in an indefinite singular context such as:

• en ny kollega

So:

• en ny kollega
• vores nye kollega

That contrast is very common in Danish adjective inflection.