快…了 / 要…了 — something is about to happen
Wrap the event in 快…了 or 要…了 to say it is about to happen: 要下雨了 — it's about to rain. 快要…了 and 就要…了 are stronger versions; only 就要…了 can take a stated time.
Structure
-
快 + Verb/Adj + 了
快下雨了 — it's about to rain.
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要 + Verb + 了 / 快要 + Verb + 了
The same, slightly more emphatic.
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Time + 就要 + Verb + 了
明天就要考试了 — the exam is tomorrow already.
How it works
This is a bracket: something goes in the middle and the sentence-final 了 closes it. 要下雨了。 (It's about to rain.) 快十二点了。 (It's nearly twelve.) The 了 is the change-of-state one — the situation is on the verge of being different.
The four variants shade from mild to insistent: 要…了 → 快…了 → 快要…了 → 就要…了. In everyday speech they are close enough to swap freely.
One structural difference matters. Only 就要…了 can carry a stated time. 明天就要考试了。 is correct; 明天快要考试了 is not — 快 means "soon" and refuses to be pinned to a date.
Do not drop the final 了. Without it the sentence loses the "about to" reading entirely: 要下雨 just means "it will rain" or "it needs to rain".
Examples
Quick drill — 5 questions
Five fill-in-the-gap questions built from the example sentences above. No sign-up, no score kept — just a check that the pattern has actually landed.
Choose the word that belongs in the gap:
Common mistakes
| ✗ Wrong | ✓ Right | Why |
|---|---|---|
| 要下雨。 | 要下雨了。 | Without the closing 了 the "about to" meaning disappears. |
| 明天快要考试了。 | 明天就要考试了。 | 快 cannot be tied to a stated time. Only 就要 accepts one. |
| 火车快要开。 | 火车快要开了。 | The bracket must be closed — 快要…了 is a pair, not a prefix. |
快…了 / 要…了 — about to happen — frequently asked questions
How do you say "about to" in Chinese?
Wrap the event in 快…了 or 要…了: 要下雨了 (it's about to rain), 快十二点了 (it's nearly twelve). The final 了 is required — it marks the change of state.
What is the difference between 快要…了 and 就要…了?
Both mean "about to", but only 就要…了 can be used with a stated time: 明天就要考试了 (the exam is tomorrow already). 快 means "soon" in a vague sense and cannot be pinned to a date.
Can you drop the 了 in 要…了?
No. Without it, 要下雨 means "it will rain" or even "rain is needed" — the imminence is carried entirely by the closing 了.
Is 要…了 the future tense?
No, Chinese has no tenses. 要…了 says an event is on the verge of happening; a plain future is expressed with a time word (我明天去) or with 会 for likelihood (明天会下雨).
Next, learn
Put it to work
Drill the vocabulary for this level on the HSK 2 word list, rebuild scrambled sentences in the Sentence Builder, read graded stories that use this pattern in the story library, or follow a step-by-step route through the whole site in Guided Learning Paths.