This is the 10111th most frequent Polish word.
biletu
"Biletu" means "ticket" (genitive singular form) in English.
In this sentence, 'biletu' is used in the genitive case, which often happens when paired with verbs like 'forget' (zapomnieć), indicating necessity or ownership.
Nie mogę zapomnieć biletu na koncert.
I cannot forget the ticket for the concert.
Here, 'biletu' is in the genitive case, used to specify something belonging to or associated with the ticket (its number).
Czy masz numer biletu do rezerwacji?
Do you have the ticket number for the reservation?
This instance of 'biletu' reflects possession or association using the genitive case, showing a part of something related to the ticket.