Expressing "almost" using "chadian mei"
Logically, 差点没 (chàdiǎn méi) is just a simple extension of 差点, adding the negation after it. In fact, you shouldn't think of it as a single word; think of the 没 as belonging to what follows 差点 and it makes more sense. Still, it can be a little confusing for many learners, and is worth a closer look.
Obviously, 差点 and 差点儿 are equivalent here.
Subj. + 差点 + 没 + Verb Phrase
Note that the "Verb Phrase" part is a desired result. So this structure is literally saying, "almost didn't [Verb Phrase]."
Also note that because you're using 没, you don't use 了 after the verb phrase.
- 我 差点儿 没 想 起来。I did recall it.I almost couldn't recall it.
- 我 差点 没 赶 上 火车。 I almost missed it, but I didn't.I almost missed the train.
- 他 差点 没 通过 考试。He did pass it, but almost didn't.He barely passed the examination.
- 我 差点儿 没 拿到 签证。I almost didn't get the visa.
- 排队 的 人 太 多 了，差点儿 没 买到。I did get it.The waiting line is too long. I almost didn't get it.
- 他们 两个 差点儿 没 通过 面试 。The two of them almost didn't pass the interview.
This is the weird one. In the following usages, 差点 and 差点没 are equivalent. It's almost as if the 没 is meaningless. You can literally drop it with no change in meaning, but only when there is an undesired result after 差点没.
Subj. + 差点 (+ 没) + Verb Phrase
In this pattern, the "Verb Phrase" part is an undesired result. So in terms of meaning, this structure is identical to the regular 差点 structure.
Again, because you're using 没 here, you don't use 了 after the verb phrase.
- 我 差点儿 没 和 她 撞 在 一起。I almost ran into her.
- 这个 地方 太 大 了，我 走 了 很 久，差点儿 没 累 死。This place is so big. I walked for so long I almost died from exhaustion.
- 我 差点儿 没 被 发现。I was almost discovered.
- 这里 差点儿 没 变成 一 个 垃圾场。This place has almost become a dump.
Sources and further reading
- 现代汉语八百词（增订本） (pp. 112) [ →buy]
- 现代汉语词典（第5版） (pp. 145) →buy