[译] 她答应要帮助我。
[误] She gave me the promise of helping me.

[正] She gave me the promise to help me.
[注] 表示“答应某人做某事”，应该说 give sb. a promise to do sth., 其中在 promise 后必须使用动词不定式，而不能用“of + 动名词”的结构。