I promised him/her
Je lui ai promis de ne rien répéter.
I promised him I wouldn't repeat anything.
Je lui ai promis de garder ça secret.
I promised him I'd keep it a secret.
Je lui ai promis de faire du cross au Bois de Boulogne.
I promised her I’d go running in the Bois de Boulogne.
— The Tall Blond Man with One Black Shoe (1972)
Je lui ai promis de ne pas le lui dire.
I promised him I wouldn't tell him.
Je lui ai promis qu'on irait ensemble.
I promised him/her that we would go together.
— Dernier train pour Busan (2016)
Je lui ai promis que je viendrais aujourd'hui.
I promised him/her that I would come today.
Je lui ai promis de ne rien dire.
I promised him I wouldn't say anything.
Je lui ai promis que je ne le ferai plus.
I promised him I wouldn't do it again.