Jaygee

[Jaygee]

In the English language what is the correct way to discribe phrases like:
you should have come, and not you should have came; he did not go, and not he did not went; How do I explain why the grammer is like this?

[Casiopea]

The verb have takes a past participle, as in [1]. In [2], came is not a past participle. It's the past tense of the verb come:

[1] You should have come. <past participle>
[2] You should have came. <past tense>

In English, only one verb per simple sentence can carry tense, as in [3]: the verb did carries tense, and the bare infinitive verb go doesn't carry tense. In [4], there are two tense-carrying verbs: did and went:

[3] He did not go.
[4] He did not went.

Does that help?