to do表目的/Do开头祈使句/Doing放句首作主语的三种情况：

1、动词原形开头的祈使句：动词原形直接作祈使句的谓语，表示命令、请求、建议等。例句：Watch your step!

Do被用来加强陈述语气，表示一种强烈的感情或请求。 在这种情况下，Do后跟着一个动词的原形。 例句：Do tell me more about your trip.（一定要告诉我更多关于你旅行的事情。）

2、表示目的：to + 动词原形用于表示为达到某一目的所做的事情，可翻译成“为了”。

例句：To make pancakes, you will need flour, eggs, and milk.（要做煎饼，你需要面粉、鸡蛋和牛奶。）

另外，To do也可以作主语，但一般较少，需要注意前后一致，例如：To see is to believe.眼见为实。 这句话也可表达为：Seeing is believing.

3、动词ing放句首作主语：用于表示某件事情，作主语，当单数名词。

例句：Doing yoga in the morning helps me stay calm and focused all day.（早上做瑜伽可以帮我整天保持冷静和专注。）

做题方法

总结：找谓语，缺谓语，用动词原形do，祈使句。

            不缺谓语，一般有逗号隔开，有主有谓，用To do表目的，“为了”；

            不缺谓语，无逗号，有谓无主，用动词ing形式，作主语；

注意：“一连二谓”，判断是否有连词的情况。

解题思路

习题-Exercises

【训练】按括号所给单词形式填空的题目：

cook:

    ________ a good meal, you need fresh ingredients.

    ________ the pasta for 10 minutes in boiling water.

    ________ dinner for my family is something I enjoy doing.

study:

    ________ hard is the key to academic success.

    ________ every day to improve your English skills.

    ________ for exams can be stressful, but it’s necessary.

play:

    ________ the piano well, you need to practice regularly.

    ________ the song one more time, please.

    ________ sports is a great way to stay healthy and active.

write:

    ________ a novel, you need a good plot and interesting characters.

    ________ your name and address on the envelope.

    ________ poetry is a form of self-expression.

sing:

    ________ in a choir can be a wonderful experience.

    ________ your favorite song for us, please.

    ________ in the shower is a common pastime for many people.

dance:

    ________ is a great way to exercise and have fun.

    ________ to the music and let your body move freely.

    ________ in the competition, he practises hard day and night.

read:

    ________ books is a great way to learn new things.

    ________ this article and then answer the questions.

Do, To do, Doing放句首的三种情况最先出现在Clarissa Study。