直到【zhídào】

直到 means "until" or "all the way up to". It sits before a time or an event and stretches the situation right up to that point. Its usual partner is 才 in the second half: the thing happened only then, and later than expected.

The 直到 phrase can stand before the subject with a comma, or right after the subject.

"Not until" takes 才, not 不

English says "didn't … until". Chinese states the event positively and puts 才 before it.

• × 我直到十二点没睡 → 我直到十二点才睡
• × 直到昨天我不知道 → 直到昨天我才知道

With 还 or 都: "even then"

With 还 or 都, the situation is still going at that point. 直到现在 is "even now, to this day".

一直 also stretches something over time, but it goes before the verb and 到 marks the end point: 我一直等到十点 "I waited all the way until ten". 直到 heads the time phrase itself.