Learn Hardcore Polish: Szafa w sypialni jest mała, ale trzymam tam koszule. - The wardrobe in the bedroom is small, but I keep shirts there.

It’s the Locative case. The preposition w means “in” (static location) and requires the Locative, so sypialnia (bedroom) becomes sypialni in the Locative singular: w sypialni = “in the bedroom.”

Why is it sypialni and not sypialnia, sypialnię, or sypialnie?

sypialni is Locative singular (after w for “in”): correct here.
sypialnia is Nominative singular (dictionary form).
sypialnię is Accusative singular (used after certain prepositions or as a direct object), but not used for static “in.” For movement “into,” Polish prefers do sypialni (“to/into the bedroom”), not w sypialnię.
sypialnie is Nominative plural (“bedrooms”) or Accusative plural, not needed here.

What does trzymam mean exactly, and how is it different from mam?

trzymam (from trzymać) = “I keep/store” or “I hold.” It implies the shirts are kept/placed somewhere.
mam (from mieć) = “I have/own.” It doesn’t say anything about where they are kept. In this sentence, trzymam is natural because it focuses on storage location.

Why is koszule used here? What form is it?

koszule is the Accusative plural of koszula (a shirt, usually a dress shirt). It’s the direct object of trzymam. Feminine nouns in the plural often have Accusative = Nominative, so Npl = koszule, Accpl = koszule.

When would I use koszulę instead?

koszulę is Accusative singular (one shirt). For example:

Trzymam tutaj jedną koszulę. = “I keep one shirt here.”

Why not koszul? I’ve seen that form too.

koszul is the Genitive plural. You use it:

after negation: Nie trzymam tam koszul. = “I don’t keep shirts there.”
with certain quantity words: dużo/niewiele/pełno koszul = “a lot of/few/plenty of shirts.”

Why is the adjective mała and not mały or małe?

Agreement. szafa is feminine singular, so the adjective is feminine singular nominative: mała. For reference:

masculine: mały (np. mały pokój)
feminine: mała (np. mała szafa)
neuter: małe (np. małe okno)

Can I change the word order with tam? For example, Tam trzymam koszule?

Yes. Polish word order is flexible:

Trzymam tam koszule (neutral).
Tam trzymam koszule (emphasizes the place).
Trzymam koszule tam (also possible; final position can add focus to “there”). All are acceptable; choose based on what you want to emphasize.

Does tam refer to the wardrobe or the bedroom? Is it ambiguous?

It can be a bit ambiguous: it might refer to the wardrobe (most likely in context) or to the bedroom. To be precise, you can say:

Trzymam w niej koszule. = “I keep shirts in it.” (w niej refers to szafa)
Trzymam w sypialni koszule. = “I keep shirts in the bedroom.”

Is w niej the correct pronoun after w? Why not w nią?

Yes, w niej is correct. After w for location, you need the Locative case. The feminine pronoun ona has Locative niej. w nią would be Accusative and is wrong for static “in.”

Do I need jest? Could I say Szafa w sypialni mała?

In standard Polish you need the verb być in the present: Szafa w sypialni jest mała. Dropping jest is not correct here. An alternative structure is with to: Szafa w sypialni to mała szafa, but that repeats the noun and sounds a bit heavy in this context.

Why is there a comma before ale?

Polish punctuation requires a comma before ale when it links two clauses or contrasting parts: …, ale …. You can sometimes use lecz instead of ale (more formal/literary), and you still keep the comma.

Why w sypialni and not na sypialni?

For being inside a room, Polish uses w + Locative: w sypialni. na is for surfaces or certain set locations/contexts (e.g., na stole, na uniwersytecie), not for “inside a bedroom.”

Polish has no articles, so how do I know if szafa means “a wardrobe” or “the wardrobe”?

Context. Szafa w sypialni can mean “the wardrobe in the bedroom” or “a wardrobe in the bedroom.” If you need to make it specific, you can use demonstratives:

ta szafa = “this/that wardrobe”
w tej sypialni = “in this/that bedroom”

Is there any difference between szafa, szafka, and garderoba?

szafa: a full-size wardrobe/closet (often for clothes).
szafka: a smaller cupboard/cabinet (diminutive feel).
garderoba: a walk-in closet/dressing room, or a wardrobe collection.

Could I say Trzymam tam koszulki if I mean T‑shirts?

Yes. koszulka = T‑shirt. Be aware of the difference:

koszula: a dress shirt with buttons/collar.
koszulka: a T‑shirt or undershirt. So: Trzymam tam koszulki = “I keep T‑shirts there.”

Does Polish have a present continuous like “I am keeping”? How does trzymam map to English tenses?

Polish has one present form that covers both simple and continuous meanings. Trzymam can mean “I keep” or “I am keeping,” depending on context. Aspect is expressed differently (imperfective trzymać vs. perfective forms like potrzymać for “hold/keep for a while”).

Any pronunciation tips for this sentence?

sz in Szafa = English “sh.”
trz in trzymam is pronounced like “tsh” + a voiced “zh” sound for rz (approx. [tʂɨ-mam]).
ł in mała = English “w.”
ń in sypialni is a soft “ny” sound. Say it smoothly: “SHA-fa v syp-YAL-nee yest MA-wa, a-le CHI-zhy-mam tam ko-SHOO-le.”