be going to/be about to/will 都用來(lái)表將來(lái)時(shí),但細(xì)究起來(lái)意思稍有不同.
be going to do 將要做（計(jì)劃好了）
be about to do 正準(zhǔn)備去做
will do 將會(huì)去做（沒(méi)有特別計(jì)劃,只表示動(dòng)作將會(huì)發(fā)生,有時(shí)也表示愿望）
will going to do 沒(méi)有這種表達(dá)方式,可能是 will be going to,指將會(huì)去哪里
幾個(gè)例句：
Tom's going to spend his vacation abroad.湯姆計(jì)劃在國(guó)外度假.
I was about to call you when you knocked the door.你敲門(mén)的時(shí)候我正要打電話給你.
I will see you at the airport.我會(huì)到機(jī)場(chǎng)見(jiàn)你（我們機(jī)場(chǎng)見(jiàn)）.
Will you marry me in 3 years time?I will.你三年后會(huì)嫁給我嗎?我會(huì)（表示愿意）.