Na wieszaku obok drzwi jest też moja mokra bluza.

Because na is describing a location here, not movement.

In Polish, when na means on / at in a static sense, it normally takes the locative case.
So:

• wieszak = base form
• na wieszaku = on the hanger / on the coat rack

Compare:

• bluza jest na wieszaku = the sweatshirt is on the hanger
• kładę bluzę na wieszak = I put the sweatshirt onto the hanger

So na + locative is used for location, while na + accusative is often used for movement toward something.

Wieszak can mean a few related things:

• a hanger
• a coat rack
• sometimes a hook / hanging stand, depending on context

Because the sentence says obok drzwi (next to the door), many learners would imagine a coat rack or some kind of wall hanger near the door, not necessarily a thin clothes hanger in a closet.

So the exact English word depends on the situation, but the Polish is completely natural.

Obok takes the genitive case.

So after obok (next to / beside), the following noun should be in the genitive.

The tricky part is that drzwi is a special noun:

• it means door
• but grammatically it is plural-only in Polish

That means Polish treats drzwi like a plural noun even when English uses singular door.

Its genitive form is also drzwi, so you do not see a visible change here.

So:

• obok drzwi = next to the door

This is just one of those vocabulary facts you have to learn.

Some Polish nouns are pluralia tantum, meaning they exist only in plural forms. Drzwi is one of them.

Other common examples include:

• nożyczki = scissors
• spodnie = trousers/pants

So even when talking about a single door, Polish uses the plural-form noun drzwi.

That is why you get things like:

• te drzwi = this door / these doors, depending on context
• obok drzwi = next to the door

Because the real subject is moja mokra bluza, and that is singular.

The sentence begins with a location phrase:

• Na wieszaku obok drzwi = on the hanger / coat rack next to the door

Then comes the verb:

• jest = is

Then the subject:

• moja mokra bluza = my wet sweatshirt/hoodie

So even though the sentence starts with a longer phrase, the thing that is there is still one item: bluza.
That is why the verb is singular: jest.

Because they both agree with bluza.

Bluza is:

• feminine
• singular
• nominative here

So the words describing it must match that:

• moja = my
• mokra = wet
• bluza = sweatshirt / hoodie

This is called agreement. In Polish, adjectives and possessive words usually match the noun in gender, number, and case.

If the noun changed, those forms would change too. For example:

• mój mokry sweter = my wet sweater
• moje mokre ubranie = my wet clothing/garment

Yes, this is a very common learner trap.

Bluza does not usually mean English blouse.

It usually means something like:

• sweatshirt
• hoodie
• sometimes tracksuit top or a casual long-sleeved top

So if you translate it as blouse, you will usually sound wrong in English.

Też means also / too.

It adds the idea that this item is one more thing in the situation already being discussed. In English, we might naturally say also or too.

Its exact position in Polish can move around a bit, but the emphasis may change slightly.

Here:

• jest też moja mokra bluza

means roughly there is also my wet sweatshirt

The speaker is adding moja mokra bluza to the list of things that are there.

Yes. Polish word order is flexible, and different versions can sound natural depending on emphasis.

This sentence starts with the location, which is very common when introducing where something is:

• Na wieszaku obok drzwi jest też moja mokra bluza.

Other possible orders include:

• Moja mokra bluza też jest na wieszaku obok drzwi.
• Też jest na wieszaku obok drzwi moja mokra bluza.
• Na wieszaku obok drzwi też jest moja mokra bluza.

These do not all feel exactly the same in emphasis, but they are understandable.
The original version sounds natural if the speaker wants to begin with where the item is.

Polish often simply uses jest (is) where English uses there is.

So instead of needing a separate dummy subject like English there, Polish can just say:

• Na stole jest książka. = There is a book on the table.
• W pokoju jest kot. = There is a cat in the room.

That is exactly what is happening here too.
The sentence structure is very natural in Polish: location first, then jest, then the thing located there.

Because Polish usually does not need one here.

The noun moja mokra bluza is stated explicitly, so adding a pronoun would be unnecessary.

Polish often leaves out subject pronouns unless they are needed for contrast or emphasis. Since the sentence already names the item, no extra pronoun is required.

Both are possible in some contexts, but moja mokra bluza is the more neutral and natural order.

In Polish, possessives like mój / moja / moje often come before descriptive adjectives:

• moja mokra bluza
• twój nowy telefon
• nasz stary dom

If you change the order, you may create a different emphasis or a more marked style. So for a learner, moja mokra bluza is the safest and most natural choice.

Yes, very normal.

The pattern:

• [location] + jest + [thing]

is common in everyday Polish when saying where something is or when introducing something present in a place.

So this sentence sounds natural and conversational, especially if someone is listing things hanging or lying around near the door.