要⋯⋯了
yào …… le
Expressing "be going to" with "yao"
要…了 is the near future — it's about to happen.
Subj. + 要 + Verb (+ 了)
How it works
我要去吃饭，你去吗? — I'm off to eat, coming? With a closing 了 the imminence is stronger: 要下雨了.
快要…了 and 就要…了 are the emphatic versions; 就要 additionally allows a stated countdown.
Examples
wǒ yào qù chī fàn, nǐ qù ma?
我要去吃饭，你去吗？
I'm going to eat — coming?
yào xià yǔ le
要下雨了。
It's about to rain.
wǒ men yào zǒu le
我们要走了。
We're leaving.