不定式作表语是英语语法中的一个常见现象，它通常跟在系动词（如be, become, seem等）后面，用来描述主语的状态、特征或目的。以下是一些关于不定式作表语的例句和解释：
表示目的
My work is to clean the room every day.
His dream is to be a doctor.
Her wish is to travel around the world.
表示状态或特征
The key to success is to work hard.
My goal is to learn Chinese.
Her hobby is to sing and dance.
表示未来的动作
To do two things at a time is to do neither.
What I would suggest is to start work at once.
表示被动关系
He is leaving for the conference next week, all expenses to be paid by his company.
He loves her, all housework to be done by her.
用于第一人称疑问句，表示征求意见
To be or not to be, that is the question.
注意事项
不定式作表语时，常常需要加上“to be”或“to become”等连接动词，以使句子更加完整。
不定式作表语时，通常放在系动词之后，例如“be”､“become”､“seem”等。
通过这些例句和解释，我们可以看到不定式作表语在英语中的广泛应用和重要性。它不仅可以用来表达目的和愿望，还可以描述主语的状态和特征，甚至在某些情况下表示被动关系。希望这些信息对你有所帮助。