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.
Subject + 要 + Verb
- 我 要 去 你家 吃 晚饭 。 I'm going to your place to have dinner.
- 我 今 年 要 学 中文 。 I am planning to learn Chinese this year.
- 我 下 个 月 要 去 中国 工作 。 I am going to China to work next month.
- 星期天 我 要 去 北京 。 I am going to Beijing on Sunday.
- 我 等会儿要 给 妈妈 打电话 。 I am going to call my mom in a little bit.
- 我 要 出去。 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.
- 你 明天要 回 美国 吗？ Are you going back to the U.S. tomorrow?