依照主词做现在式的词形变化 + about + 主要动词的不定词
|主词||+ to be||+ about（或 just about）||+ 不定词|
|I||am||about||to be sick|
|It||is||just about||to explode.|
即刻的将来，以 to leave 为例
|I am about to leave.||I am not about to leave.||Am I about to leave?||Am I not about to leave?|
|You are about to leave.||You are not about to leave.||Are you about to leave?||Aren't you about to leave?|
|He is about to leave.||He is not about to leave.||Is he about to leave?||Isn't he about to leave?|
|We are about to leave.||We aren't about to leave.||Are we about to leave?||Aren't we about to leave?|
|They are about to leave.||They aren't about to leave.||Are they about to leave?||Aren't they about to leave?|
- She is about to cry.
- You are about to see something very unusual.
- I am about to go to a meeting.
- We are just about to go inside.
- Sally is just about to jump off that diving board.
若谈论的是过去即将发生丶但被打断的事，也可以将此句型的现在式 Be 动词改为一般过去时的 Be 动词。这样的句型通常后面会接一个以「when」引导的子句。
- She was about to leave when Jim arrived.
- When it started to rain, I was about to go out for a walk.
- I was just about to call her when she walked in.
- The car was just about to flip over when he regained control.