前脚

1. the forward foot in a step

♦ 我~一滑, 身体站不稳, 就摔了。 As soon as my front foot slipped, I lost my balance and fell over.

2. (used together with 后脚) no sooner...than; the moment (when)

♦ 你~走, 他后脚就来了。 He arrived the moment you had left.