Hayley教口語，“說一聲”用英語怎么說？

to give a signal to begin; to tell someone that you will do what they want at the time they ask you

給一個(gè)開始的信號(hào);吩咐一下，說一聲，表示一下

If you need any help, just say the word.

需要我們幫忙你就說。

You only have to/Just say the word, and I'll come and help.

你只要說一聲，我就會(huì)來幫忙。

I'm ready to start any time you say the word.

只要你說一聲，我就準(zhǔn)備開始。