He who hesitates is lost.

迟疑者必有失。

I know that he who hesitates is lost.

我知道，犹豫着终难成事。

I know that he who hesitates is lost.

我知道，犹豫者终难成事。

Call that girl and ask her out. Call her right now. He who hesitates is lost.

打电话给那女孩，跟她约会，现在就打电话给她。踌躇不决者必然失败。