You may know auxiliary verbs by other names, such as "helping verbs" (since the usually precede verbs and "help" them), "modal verbs" (since the often express a kind of mood) or even by their common abbreviation: aux. They add meaning to verbs, expressing need, ability, or desire.

Common auxiliary verbs include 要, 想, 会, 能, 可以, 应该, 得.

Chinese auxiliary verbs have the following grammatical features:

1. Come before verbs, in the simple pattern: Aux V

   Examples:

   • 我想去学校。 I would like to go to school.
   • 学生应该学习。 Students should study.
   • 冬天会下雪吗？ Will it snow in winter?

2. They are negated by 不, the adverb of negation, which comes before them in the pattern: 不 Aux

   Examples:

   • 他不会做菜。 He can't cook dishes.
   • 我不要结婚。 I don't want to get married.
   • 他不想上班。 He doesn't want to go to work.

3. Some auxiliary verbs (想, 会, 能, 可能, 愿意) are frequently modified by 很 in the pattern: 很 Aux

   Examples:

   • 他很会说话。 He can really talk.
   • 我很愿意。 I'm happy to.
   • 我很想走。 I would really like to leave.

4. Some auxiliary verbs (要, 想, 会, 能, 得) may be preceded by 一定 to indicate a high degree of certainty in the pattern: 一定 Aux

   Examples:

   • 明天你一定要来。 You definitely must come tomorrow.
   • 你这么做，以后一定会后悔的。 If you do this, you will definitely regret it later.
   • 有了大家的支持，我一定会成功的。 With everyone's support, I will certainly succeed.
   • 只要你努力学习，就一定能考上大学。 You will definitely be accepted into a university if you study hard.
   • 明天你一定要来。 You definitely must come tomorrow.

5. With the exceptions of 应 and 得, auxiliary verbs can form a sentence all by themselves, as in an answer to a question.

   Examples:

   • 你要走吗？——要。 Do you have to go?——Yes.
   • 你想喝茶吗？——想。 Would you like to drink tea?——Yes.
   • 你会说中文？——会。 You can speak Chinese?——Yes.

6. Can form question of the pattern: Aux 不 Aux

   Examples:

   • 我能不能借钱？ Can you lend money?
   • 你要不要喝酒？ Do you want to drink (alcohol)?
   • 会不会出事了？ Could there have been an accident?

7. Cannot normally be immediately followed by aspectual particles 了, 着, 过. The aspectual particle should come after the verb, not immediately after the auxiliary verb, in the following pattern: Aux V Part

   Examples (both correct and incorrect):

   • 我现在会做菜了。 I can cook now.
   • 我现在会了做菜。
   • 我们很快就能完成工作了。 We can finish the work very soon.
   • 我们很快就能了完成工作。
   • 他得休息了。 He must have a rest.
   • 他得了休息。

8. Some auxiliary verbs can be used consecutively before a verb, as in the pattern: Aux1 Aux2 V

   Examples:

   • 他应该会帮助你的。 He will most likely help you.
   • 太晚了，我得要回家了。 It's too late. I have to go home.
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