直到 … ，… 才 … (all the way until)

Waiting until midnight

• You stayed up for your sister's flight to land; she only messaged you at midnight.
• I我wǒcontinuously一直yì zhíto wait until等到děng dào十二点shí èr diǎn，she / her她tāonly then才cáito / for / give给gěiI我wǒhair发fānews消息xiāo xī。 — "I waited right up until twelve before she messaged me."

not until直到zhí dào + time / event，… only then才cái …

• not until直到zhí dào + time/event = "right up until"; the result follows with only then才cái: something happened only then.
• not until直到zhí dào often comes first: not until直到zhí dàoyesterday昨天zuó tiān，I我wǒonly then才cáiknew知道zhī dào这件zhè jiànmatter事shì.

not until直到zhí dàoyesterday昨天zuó tiān，I我wǒonly then才cáiknew知道zhī dàothis这件事zhè jiàn shì。

Late discoveries and long waits

• not until直到zhí dàograduation毕业bì yè，he / him他tāonly then才cáiclear明白míng báiteacher老师lǎo shīif (coming after a…的话de huà。 — "It wasn't until he graduated that he understood what the teacher meant."
• With continuously一直yì zhí…until到dào: the rain雨yǔcontinuously一直yì zhífall下xiàuntil到dàothe evening晚上wǎn shang。 — "The rain kept falling until the evening."

the rain雨yǔcontinuously一直yì zhífall下xiàuntil到dàothe evening晚上wǎn shang。

Use only then才cái for the delayed result

not until直到zhí dào versus until到dào

• until到dào alone after a verb gives the end point: we我们wǒ menplay玩wánuntil到dàoten o'clock十点shí diǎn — "We played until ten."
• not until直到zhí dào stresses how long it took before something finally happened.

we我们wǒ menplay玩wánuntil到dàoten o'clock十点shí diǎn。

Recap

Read the full reference: HSK 3 grammar — Prepositions.