be to do的用法详解
一、be to do的用法解析
1. be to do作"被期望、被要求"解
  1.1 表示按计划或安排要做某事
      "I am to attend a meeting tomorrow." (我明天要参加一个会议。)
  1.2 表示按照规定或命令必须做某事
      "You are to submit your report before the deadline." (你必须在截止日期之前提交报告。)
  1.3 表示别人期望或希望你做某事
      "She is to sing at the concert tonight." (她今晚要在音乐会上唱歌。)
2. be to do用于强调将来发生的动作或事件
  2.1 表示根据安排或计划，某事将在未来发生
      "The performance is to take place next week." (演出将在下周进行。)
  2.2 强调确定性和义务
      "He is to complete the project by the end of this month." (他必须在本月底之前完成这个项目。)
3. be about to do表示即将发生的动作或事件
  "I was about to leave when he called me." (当他打电话给我时，我正准备离开。)
4. be going/gonna + 动词原形表示即将发生的动作或事件。
  "They were going to start a new project." (他们打算开始一个新项目。)
二、be to do的用法示例
1. 各类期望和要求
  1.1 The students are to complete the assignment by tomorrow.
      (学生们需要在明天之前完成作业。)
  1.2 We are to attend a conference next month.
      (我们下个月要参加一次会议。
2. 确定性和义务
  2.1 The flight is to depart at 9 am sharp.
      (航班将在上午9点准时起飞。)
  2.2 She is to give a presentation at the meeting.
      (她将在会议上进行报告。)
3. 将来发生的动作或事件
  3.1 The concert is to be held in the new auditorium.
      (音乐会将在新礼堂举行。)
  3.2 He is to start his new job next Monday.
      (他下周一开始新工作。)
4. 即将发生的动作或事件
  4.1 I was about to leave when my phone rang.
      (当我的手机响起时，我正准备离开。)
  4.2 She was about to go shopping when it started raining.
      (当下雨开始时，她正准备去购物。)
5. be going/gonna + 动词原形
  5.1 They were going to visit their grandparents for the weekend, but their plans changed suddenly.
      (他们打算周末拜访祖父母，但计划突然改变了。)
be about to
  5.2 We were gonna have a picnic, but the weather didn't cooperate.
      (我们本打算野餐，但天气不合适。)
三、总结
be to do用于表示某事被期望、要求或安排。它可以强调将来发生的动作或事件，并且表达确定性和义务。与之相似的是be about to do，它也表示即将发生的动作或事件。另外，be going/gonna + 动词原形也可表示即将发生的动作或事件。掌握这些用法对于正确理解和运用英语语法至关重要。

版权声明：本站内容均来自互联网，仅供演示用，请勿用于商业和其他非法用途。如果侵犯了您的权益请与我们联系QQ:729038198，我们将在24小时内删除。