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 我 要 去 北京。 I am going to Beijing 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？ I am going out.
- 我 明天 要 买 一 个 iPhone。 I am going to buy an iPhone tomorrow.
- 下班 以后 你 要 去 哪里 ？ Where are you planning to go after work?
- 我 下午要 去 你 家。 I am going to your place this afternoon.
- 明天 你 要 回 美国 吗？ Are you going back to the U.S. tomorrow?