The words manner, manor sound the same but have different meanings and spellings. Why do manner, manor sound the same even though they are completely different words?
The answer is simple: manner, manor are homophones of the English language.
A way of doing something or the way in which a thing is done or happens. See Synonyms at method.
A way of acting; bearing or behavior.
The socially correct way of acting; etiquette.
The prevailing customs, social conduct, and norms of a specific society, period, or group, especially as the subject of a literary work.
A landed estate.
The main house on an estate; a mansion.
A tract of land in certain North American colonies with hereditary rights granted to the proprietor by royal charter.
The district over which a lord had domain and could exercise certain rights and privileges in medieval western Europe.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.