Si Antonio estuviera en la fiesta, el hablaria con Juan.
This sentence means - If Antonio had gone to the party, he would have talked to Juan.
It is a hypothetical sentence, meaning that it didn't happen but states what could have happened had he decided to go to the party.
De vez en cuando pagaba las cuentas del hotel con tarjeta de crédito.
Donde esta la fiesta?
Cuando es el festival de arte?
Por que tu no sabes aleman?
(Thats all I got right now, I hope I somewhat helped you.)
You watched a movie at the cinema last friday
Bebo jugo de naranja y como tostadas. Cuando mi amiga se unió a mí, compartí el jugo y las tostadas con ella, y comimos juntos.