be about to和be going to的用法區(qū)別

1. be about to意爲(wèi)“就要、即將乾某事”，指最近的將來，表示動(dòng)作馬上就要發(fā)生。如：

Don't leave now. We are about to have lunch.

2. be going to意爲(wèi)“即將、打算乾某事”，表示對(duì)某事事先有準(zhǔn)備、有計(jì)劃或有打算，也可表示預(yù)計(jì)要發(fā)生或不可避免要發(fā)生的事。如：

Look，it's cloudy. It's going to rain.

注意：

be about to本身已清楚地表示出即將到來的短暫時(shí)刻，故句子中不能與at once，immediately及表示具躰的將來的時(shí)間連用。如：

I'm about to go.（不能說成：I'm about to go at once.或I'm about to go tomorrow.）