Are the given sentences correct?

1: He is a very mannerful person.
2: He is a mannerless person.

In your essay, what did you want 'mannerful' to mean?

#2 is fine. #1 is constructed correctly, but I'm not sure if "mannerful" is actually a recognised word. It seems plausible but I can't find it in any dictionaries. The words usually used are "well-mannered"/"mannerly" (which mean pretty much the same thing) and "mannered" (which is slightly different, having connotations of mannerism and affectation). I'm not sure exactly which of these meanings "mannerful" ought to have.
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i could not find the word "mannerful" in any dictionaries either.
In some places, i type it in the search bar and the sign appears, that red fuzzy line under the word, noting that i misspelled a word or something.
I hope it is a word because I used it in my essay
 Clive's reply was promoted to an answer.

mannerful is not a word.

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Yes, I believe so

First one is not correct

It will be he has is a well Mannered person.

Second one is alright

I want to say that the boy in the colony was a very mannerful one.

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Do you perhaps mean this?

eg He was very polite

eg He had very good manners.