Nearly happened: suýt (nữa thì)

Suýt before a verb says something nearly happened but didn't, usually something bad you only just escaped: Em suýt té. I nearly fell. Hôm qua anh suýt bị xe đụng. Yesterday I nearly got hit by a car. The verb after it is what nearly happened, so there's no không: Em suýt quên means I nearly forgot, and didn't.

To tell it as a little story, put suýt nữa at the start and là before what nearly happened: Suýt nữa là trễ chuyến bay. In everyday Saigon speech you'll also hear xém (Xém té rồi!) and chút nữa là or xíu nữa là: Chút nữa là mình trễ chuyến bay rồi. We nearly missed our flight. In Hà Nội it's tí nữa thì: Tí nữa thì quên.

Compare gần như (almost), which describes something that's nearly complete or nearly true: Quán gần như hết chỗ. With suýt, the thing didn't happen at all.