Die Bluse sitzt locker, aber der Kragen ist zu eng.

Yes, sitzen literally means to sit, but in German it is also very commonly used for the way clothing fits or sits on the body.

So Die Bluse sitzt locker means something like:

• The blouse fits loosely
• The blouse hangs loosely
• The blouse sits loosely

This is very natural German. English uses fit more often here, while German often uses sitzen for clothes.

Die Bluse ist locker is possible in some contexts, but sitzt locker is more idiomatic when talking about how clothing fits on a person.

The difference is roughly:

• Die Bluse ist locker = the blouse is loose in general
• Die Bluse sitzt locker = the blouse fits loosely on the wearer

So sitzen focuses more on the actual fit.

Here locker means loose, not tight, or relaxed in fit.

In clothing contexts:

• ein locker sitzendes Hemd = a loosely fitting shirt
• Die Hose sitzt locker = the trousers fit loosely

Be careful: locker can also mean relaxed in other contexts, depending on the sentence.

Because locker is being used as a predicate adjective, not directly before a noun.

Compare:

• eine lockere Bluse = a loose blouse
  
  • here the adjective comes before the noun, so it takes an ending
• Die Bluse sitzt locker = the blouse fits loosely
  
  • here the adjective comes after the verb, so it does not take an ending

This is a very common pattern in German.

Because der Kragen is the subject of the second clause:

• der Kragen ist zu eng

The collar is the thing that is too tight, so it is in the nominative case.

If it were a direct object, you might see den Kragen, but not here.

Eng means tight or narrow.

Zu eng means too tight or too narrow.

So:

• Der Kragen ist eng = the collar is tight
• Der Kragen ist zu eng = the collar is too tight

The word zu here means too in the sense of more than is comfortable or acceptable.

In German, zu is the normal word used before an adjective to mean too:

• zu groß = too big
• zu klein = too small
• zu weit = too wide / too loose
• zu eng = too tight

So zu eng is a fixed and very common pattern.

Because aber is joining two main clauses:

• Die Bluse sitzt locker
• aber der Kragen ist zu eng

In German, when two main clauses are connected by words like aber, und, oder, denn, a comma is often used before the conjunction when it separates full clauses. Here it is standard and natural.

That is a very common learner question.

Aber is a coordinating conjunction, not a subordinating conjunction. That means it does not send the verb to the end.

So you get normal main-clause word order after it:

• ..., aber der Kragen ist zu eng.

Compare that with a subordinating conjunction like weil:

• ..., weil der Kragen zu eng ist.

So:

• aber → normal main clause order
• weil → verb goes to the end

Yes, absolutely. Der Kragen means collar, and it can be used for many types of clothing, including:

• shirts
• blouses
• coats
• jackets
• dresses, depending on style

So der Kragen is perfectly natural with die Bluse.

In this kind of clothing context, yes, they are close opposites:

• locker = loose
• eng = tight

But they are not always exact opposites in every context. For clothes, though, they work very naturally as contrasting ideas, which is why this sentence sounds so clear:

• the blouse fits loosely overall
• but the collar is too tight

Usually, locker is the better and more idiomatic word here.

Lose exists in German, but it often suggests something is not fixed properly or detached/loose in a different sense, rather than simply comfortably loose in fit.

So for clothing fit:

• Die Bluse sitzt locker = natural
• Die Bluse sitzt lose = unusual or less idiomatic

It is in the present tense:

• sitzt = present tense of sitzen
• ist = present tense of sein

German uses the present tense very often, just like English does, to describe a current situation:

• The blouse fits loosely, but the collar is too tight.

Grammatically yes, but the meaning changes.

• und = and
• aber = but

This sentence sets up a contrast:

• the blouse is loose overall
• the collar is still too tight

So aber is the better choice because it highlights that contrast. Und would sound less precise.

Yes, very common. German often describes clothing with:

• sitzen for fit
• adjectives like locker, eng, weit
• body-part or clothing-part details like der Kragen, die Ärmel, die Schultern

For example:

• Das Kleid sitzt gut. = The dress fits well.
• Die Hose ist an der Taille zu eng. = The trousers are too tight at the waist.
• Die Ärmel sitzen locker. = The sleeves fit loosely.

So this sentence sounds natural and everyday.