Answer:
Usted nada
Explanation:
ud. means usted and the person is swimming. Usted nada.
Whatever you want to put in it
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.