If you make a promise, you should keep it.

如果你许下一个诺言，你就应该遵守它。

If you make a promise, abide by it.

你如果做出诺言，就要履行诺言。

If I make a promise, I'll keep it.

如果我许下诺言，我就遵守。

When we make a promise, we keep it.

当我们许下承诺时，我们信守诺言。

One should not easily make a promise.

一个人不应轻易许下承诺。