Am Abend koche ich eine Suppe aus Kürbis und Sellerie, während meine Freundin die Aubergine schneidet.

German main clauses usually put the finite verb in second position.

So in a basic sentence, you might say:

• Ich koche am Abend eine Suppe.

If you move Am Abend to the front for emphasis or style, the verb still has to stay in second position:

• Am Abend koche ich eine Suppe.

This is called inversion in many learner explanations.
It does not make the sentence a question. It is still a normal statement.

Am Abend means in the evening or in the evening time.

It is formed from:

• an dem Abend → am Abend

In this sentence, it refers to that part of the day when the action happens.

It is similar to abends, but not always identical in tone:

• Am Abend = in the evening / this evening period
• abends = in the evenings / in the evening generally

Examples:

• Am Abend koche ich. = I cook in the evening.
• Abends koche ich oft. = I often cook in the evenings.

Suppe is a feminine noun in German:

• die Suppe = the soup

As the direct object of koche, it is in the accusative case.
For feminine nouns, the indefinite article in nominative and accusative is the same:

• eine Suppe

So here:

• ich koche eine Suppe = I am cooking a soup / soup

Here, aus means made from or out of.

So:

• eine Suppe aus Kürbis und Sellerie = a soup made from pumpkin and celery

This is a very common German pattern for ingredients or materials:

• Saft aus Orangen = juice made from oranges
• Kuchen aus Äpfeln = cake made from apples
• eine Skulptur aus Holz = a sculpture made of wood

So aus is not about direction here; it is about material/ingredient.

When German talks about ingredients or substances in a general way, it often omits the article.

So:

• aus Kürbis und Sellerie

means:

• made from pumpkin and celery

This works much like English, where we often do not say a pumpkin and a celery when we mean ingredients in general.

You could sometimes add articles in other contexts, but here the zero-article version sounds natural because they are being named as ingredients.

Because während is a subordinating conjunction here.

Subordinating conjunctions send the conjugated verb to the end of the clause.

So:

• meine Freundin schneidet die Aubergine = main clause word order
• während meine Freundin die Aubergine schneidet = subordinate clause word order

Other common subordinating conjunctions behave the same way:

• weil = because
• dass = that
• wenn = if/when
• obwohl = although

Example:

• Ich koche, während sie schneidet.

Here, während means while.

It shows that the two actions happen at the same time:

• I cook the soup
• my girlfriend cuts the eggplant

So the sentence means that both things are going on simultaneously.

A useful note: während can also be a preposition in other sentences, but here it is a conjunction introducing a clause.

In German, a subordinate clause is normally separated from the main clause by a comma.

Since während meine Freundin die Aubergine schneidet is a subordinate clause, the comma is required:

• Am Abend koche ich eine Suppe aus Kürbis und Sellerie, während meine Freundin die Aubergine schneidet.

This is stricter than in English, where comma use can be more flexible in some cases.

Because meine Freundin is the subject of the subordinate clause.

In:

• während meine Freundin die Aubergine schneidet

the person doing the action is meine Freundin, so she is in the nominative case.

The direct object is:

• die Aubergine

So the structure is:

• meine Freundin = subject
• die Aubergine = object
• schneidet = verb

You would get meiner Freundin only in other cases, such as dative or genitive contexts.

It is accusative, because it is the direct object of schneidet.

The noun Aubergine is feminine:

• nominative: die Aubergine
• accusative: die Aubergine

So the form looks the same in both cases. That is why it may be hard to spot just by the article.

In this sentence, the function tells you the case:

• meine Freundin = subject
• die Aubergine = thing being cut, so accusative object

Yes, it could be plural in another sentence, but here singular is the natural reading:

• die Aubergine = the eggplant / aubergine

This suggests she is cutting one specific eggplant.

If it were plural, it would be:

• die Auberginen = the eggplants

So:

• ... die Aubergine schneidet = cuts the eggplant
• ... die Auberginen schneidet = cuts the eggplants

Yes. Freundin can mean either:

• female friend
• girlfriend

The exact meaning depends on context.

In many everyday contexts, meine Freundin is often understood as my girlfriend, but it can also mean my female friend. If someone wants to make the romantic meaning very clear, context usually does that.

Because in German, all nouns are capitalized.

That is a standard spelling rule, not special emphasis.

So in this sentence, all of these are nouns and therefore begin with capital letters:

• Abend
• Suppe
• Kürbis
• Sellerie
• Freundin
• Aubergine

This is one of the most noticeable differences from English spelling.

Yes, absolutely.

Both are correct:

• Am Abend koche ich eine Suppe ...
• Ich koche am Abend eine Suppe ...

The difference is mostly about focus and style.

• Am Abend koche ich ... puts more attention on when
• Ich koche am Abend ... starts more neutrally with I

German allows this kind of movement quite often, as long as the verb stays in the correct position.