Ganz gleich, ob der Hosenbund eng ist, markieren wir die Taille.

Ganz gleich, ob ... is a fixed expression meaning regardless of whether ... or it makes no difference whether ....

So the sentence structure is:

• Ganz gleich = it makes no difference / regardless
• ob ... = whether ...

This is a very common way to introduce a contrast that does not affect the main action.

Ob means whether in the sense of an indirect yes/no alternative.

In this sentence, the clause ob der Hosenbund eng ist means whether the waistband is tight.

German uses ob when English would often use:

• whether
• sometimes if (in indirect questions, not in conditionals)

So here it is not a condition like if X happens, then Y happens. Instead, it means:

• whether this is true or not, the result is the same

That is why ob fits well after ganz gleich.

Because ob introduces a subordinate clause, and in German subordinate clauses the conjugated verb usually goes to the end.

So:

• der Hosenbund = subject
• eng = predicate adjective
• ist = verb, placed at the end

Compare:

• Main clause: Der Hosenbund ist eng.
• Subordinate clause: ..., ob der Hosenbund eng ist.

This is one of the most important word-order patterns in German.

Because eng is a predicate adjective here, not an adjective directly before a noun.

After verbs like:

• sein
• werden
• bleiben

German adjectives normally do not take adjective endings.

So:

• der enge Hosenbund = the tight waistband
  adjective before a noun → ending needed
• der Hosenbund ist eng = the waistband is tight
  predicate adjective → no ending

That is why eng is correct here.

Because German main clauses usually follow the verb-second rule.

The first position in the sentence is occupied by the introductory element:

Ganz gleich, ob der Hosenbund eng ist, ...

After that, the finite verb of the main clause must come next:

• markieren = second position
• wir = after the verb

So the structure is:

1. Ganz gleich, ob der Hosenbund eng ist
2. markieren
3. wir
4. die Taille

If you started directly with the subject, you would say:

• Wir markieren die Taille.

But once the introductory clause comes first, the verb must stay in second position:

• Ganz gleich ..., markieren wir die Taille.

Der Hosenbund is in the nominative case because it is the subject of the subordinate clause:

• der Hosenbund = the thing that is tight

In der Hosenbund eng ist, the verb sein links the subject to the adjective eng.

So:

• der Hosenbund = nominative subject
• eng = predicate adjective
• ist = verb

Die Taille is in the accusative because it is the direct object of markieren.

The verb markieren takes an object: you mark something.

So here:

• wir = subject
• markieren = verb
• die Taille = direct object

Also, Taille is a feminine noun:

• nominative: die Taille
• accusative: die Taille

Since feminine singular looks the same in nominative and accusative, the form does not change.

Hosenbund is a compound noun:

• Hose(n) = trousers / pants
• Bund = band, edge, waistband area

Together, der Hosenbund means waistband, specifically the waistband of trousers or similar clothing.

German often forms nouns this way by combining smaller words into one longer noun.

Because German separates a subordinate clause from the main clause with a comma.

Here the first part is a subordinate clause introduced by ob:

• Ganz gleich, ob der Hosenbund eng ist,

Then comes the main clause:

• markieren wir die Taille.

German comma rules are stricter than English in this area, so this comma is required.

Yes. It is a common and useful pattern for saying that something does not affect the outcome.

You can use it with many different ideas, for example:

• Ganz gleich, ob es regnet, wir gehen raus.
• Ganz gleich, ob du zustimmst, ich mache es.

It often sounds a little more formal or polished than very simple alternatives, but it is perfectly natural.

Sometimes a similar idea can be expressed with auch wenn (even if / even though), but the nuance is slightly different.

• Ganz gleich, ob ... focuses on it makes no difference whether
• auch wenn ... focuses more on even if / even though

So in many contexts they may be close, but they are not always exact substitutes.

In this sentence, ganz gleich, ob ... strongly emphasizes that the tightness of the waistband does not change what the speaker does.

Not necessarily. In instructional, technical, or professional German, wir is often used in a general or procedural way, similar to English instructional we:

• first we do this
• then we mark the waist

So depending on context, wir could mean:

• the speaker and someone else
• people in general doing this procedure
• the writer and reader together in an instructional style

This is very common in guides, demonstrations, sewing instructions, fitting instructions, and similar contexts.