向某人承诺用英语怎么说

"to make a promise to someone" 可以用英语表达为 "to make a promise to someone"。
来源：Promise 这个词本身就是“承诺”的意思，而 make a promise 则表示“做出承诺”。
例句：
I promise to always be there for you. (我保证永远在你身边。)
I made a promise to my parents that I would graduate from college. (我向我父母承诺我会从大学毕业。)
I will keep my promise to meet you at the park at 3 PM. (我会信守跟你在公园3点钟见面的约定。)