Expressing "be going to" with "yao"
The idea behind this usage of 要 (yào) is that someone is "planning to" or "going to" or "preparing to" do something. It's not that they just want to, or have to, it's that they fully expect to do it. It's in their plan. This usage of 要 (yào) typically includes a time-indicating expression, which may be placed before or after the subject.
Subj. + 要 + Verb
- 我 要 去 你家 吃 晚饭。 I'm going to your place to have dinner.
- 我们 今 年 要 去 美国。 We are planning to go to America this year.
- 他 下 个 月 要 来 中国 工作。 He is coming to China to work next month.
- 这 个 星期天 你 要 做 什么？What are you going to do this Sunday?
- 我 晚上要 给 妈妈 打电话。 I am going to call my mom this evening.
- 你们 要 出去 吗？ Are you going out?
- 我 明天 要 买 一 个 iPhone。 I am going to buy an iPhone tomorrow.
- 下班 以后 你 要 回家 吗？ Are you planning to go back home after work?
- 下午 老师 要 来 我家。 The teacher is coming to my place this afternoon.
- 老板 明天要 见 客户 吗？ Are they going back to the U.S. tomorrow?