Breakdown of W tej kawiarni zamówiłam sernik, a mój chłopak pączka, bo nie miał ochoty na lody.
Questions & Answers about W tej kawiarni zamówiłam sernik, a mój chłopak pączka, bo nie miał ochoty na lody.
Because zamówiłam is the past tense, first person singular, feminine form of zamówić (to order).
So the speaker is a woman.
- zamówiłam = I ordered (said by a woman)
- zamówiłem = I ordered (said by a man)
Polish past tense usually shows the gender of the speaker in the singular.
W tej kawiarni means in this café.
It uses the preposition w (in), which here requires the locative case.
That is why the words change:
- ta kawiarnia = this café / this coffee shop
- w tej kawiarni = in this café
So:
- ta → tej
- kawiarnia → kawiarni
This is a very common pattern after w when it means location.