his promise
Tom rompió su promesa y no ayudó a Mary.
Tom broke his promise and didn’t help Mary.
No fue fácil para él cumplir su promesa.
It wasn't easy for him to keep his promise.
He must keep his promise.
Tom y María mantendrán su promesa.
Tom and Maria will keep their promise.
Don Ciccio Matara había mantenido su promesa.
Don Ciccio Matara had kept his promise.
— Divorcio a la italiana (1961)
Por lo que yo sé, él es una persona que mantiene su promesa.
As far as I know, he is a person who keeps his promises.
He forgot his promise to go there.
Él es la última persona que rompería su promesa.
He's the last person who would break his promise.
Tengo fe en que él mantendrá su promesa.
I have faith that he will keep his promise.