to his/her birthday party
No pude ir a su fiesta de cumpleaños.
I couldn’t go to his birthday party.
Ella me invitó a su fiesta de cumpleaños.
She invited me to her birthday party.
Él le explicó a Mary por qué llegaba tarde a su fiesta de cumpleaños.
He explained to Mary why he was late to her birthday party.
Daniel vino a su fiesta de cumpleaños vestido de payaso.
Daniel came to his birthday party dressed as a clown.
Ella nos invitó a su fiesta de cumpleaños.
She invited us to her birthday party.
Fue tan amable como para invitarme a su fiesta de cumpleaños.
She was kind enough to invite me to her birthday party.
Fui invitado a su fiesta de cumpleaños.
I was invited to her birthday party.