Is it ok to say "I am come"here?It is an excerpt from "Wuthering Heights"I know it is ok because it is from a classic work.But I am confused about the usage like this.

`You see, sir, I am come, according to promise!' I exclaimed, assuming the cheerful; `and I fear I shall be weatherbound for half an hour, if you can afford me shelter during that space.'

Thank you teachers!
I just finished reading Wuthering Heights (although it is a classic, I had never read it before), and a lot of the language in it is old-fashioned or archaic. I don't know if "I am come" might still be heard in British English, but to an American it definitely sounds archaic.

I'll try to watch for further questions you have about the book -- but I'm not sure how much I can help with the character Joseph. His speech is not simply archaic, but archaic dialect. It's really hard to understand.
I am come from the UK, and we don't say that.
Site Hint: Check out our list of pronunciation videos.
This book was published in 1845. Therefore the language it uses is over 150 years old so much of it will not be appropriate for contemporary use.
I am come has its roots deep in the history of the English language. In Old English (1200 years ago) there were only two tenses, the present tense and the preterite. The present tense was used to express the future as well and the preterite had the meaning of the modern past tense, continuous past, perfect and pluperfect. However, even in those days the periphrastic tenses were sometimes formed, as in Modern English, by hæbbe and hæfde with past participles and they sometimes had the meanings of the modern perfect and pluperfect respectively. Usage of tenses wasn't very settled in Old English, and there was even some usage of the future tense even though it didn't officially exist. Will often indicated volition and shall obligation, but not always.

Periphrastic tenses of intransitive verbs were formed with wesan (= to be) instead of habban (= to have), as in Modern German. This explains why we encounter is, are, was and were as perfect and pluperfect auxiliaries as late as the 19th century. It also explains why it is so easy and natural to say: He is gone.

As a phrase, I'd agree with you but as a construction it has modern echoes. "We are sat here" was the phrase I used that kicked off the query and of course in the marriage ceremony we still hear "We are gathered" (although I would allow that this as more archaic roots).

The only reason I found this thread was because I was looking for a more learned explananation for an American colleague of mine after I used the phrase above. It may simply be that this is one area where our common language (UK/US) has diverged.
Teachers: We supply a list of EFL job vacancies
but sir why don't say that
Anonymousbut sir why don't say that
It is very old-fashioned; we don't use it anymore.
Mister MicawberIt is very old-fashioned; we don't use it anymore.
Methinks thy word is spoke aright.
Students: We have free audio pronunciation exercises.