主谓一致（subject verb agreement）

一篇文章有它的主题，整篇文章都围绕着这个主题来。

一个句子也有它的主题，整个句子围绕着这个主题展开。一个句子的主题就是所谓的“主语 (subject)”.

verb 的本质涵义是“讲述”，所以 verbal 的意思是“口头的，口语的”，verbose 的意思是“唠叨的，啰嗦的”。

verb 在句子中的作用就是“讲述”主语的，可以翻译成“谓语”、“谓词”、“述词”。

主语(subject)是一句之主，是处在老大的位置。谓语(verb) 是讲述主语的，是为主语服务的，从属于主语，所以谓语要和主语保持一致。这就是英语中主谓一致(subject verb agreement)的由来。

一个句子中可能有多个 verbs. 其中必有一个 verb

我们看下面几个句子：

1. I am strong. 
2. We are strong.
3. You are strong.
4. He is strong.
5. She is strong.
6. It is strong.
7. They are strong.
8. I eat apples.
9. We eat apples.
10. You eat apples.
11. She eats apples.
12. He eats apples.
13. It eats apples.
14. They eat apples.
15. I am eating apples.
16. We are eating apples.
17. You are eating apples.
18. He is eating apples.
19. She is eating apples.
20. It is eating apples.
21. I have eaten apples.
22. We have eaten apples.
23. You have eaten apples.
24. He has eaten apples.
25. She has eaten apples.
26. It has eaten apples.
27. They have eaten apples.
28. I was strong.
29. We were strong.
30. You were strong.
31. He was strong.
32. She was strong.
33. It was strong.
34. They were strong.
35. I was eating apples.
36. We were eating apples.
37. You were eating apples.
38. He was eating apples.
39. She was eating apples.
40. It was eating apples.
41. They were eating apples.
42. I had eaten apples.
43. We had eaten apples.
44. You had eaten apples.
45. She had eaten apples.
46. He had eaten apples.
47. It had eaten apples.
48. They had eaten apples.
49. I will be strong.
50. We will be strong.
51. You will be strong.
52. She will be strong.
53. He will be strong.
54. It will be strong.
55. They will be strong.

分析上面的句子，不难发现以下几点：

1. 一个句子中可以有多个 verbs.
2. 其中的一个 verb 要在人称和数上与主语要保持一致，这个 verb, 我们称之为 finite verb.