请等一下用英语怎么说?

Please hold on a minute/hold on
hold on please
please wait a moment
one minute
just a moment
洋鬼子一般都这么说的，hold on please（较舒服些）
一般就说hold on就可以

与外国客人面谈时，你有电话或事情要离开一下：Excuse me, I have a inporttant call to answer.wait a moment please.

与外国客人通电话时，才说：hold on please.如果不知道怎么应对，就告诉他：sorry, i am busy now/i can't hear clearly, please send me your question by E-mail.
(哈哈，这样就不用担心什么吧）

hold on please请梢等不要挂
one moment/one second 一下就好

Please hold on a minute.

please hold on [简明英汉词典]
请别挂上

hold on please!打电话用语
wait a moment/minute!请等一会儿