The words summary, summery sound the same but have different meanings and spellings. Why do summary, summery sound the same even though they are completely different words?
The answer is simple: summary, summery are homophones of the English language.
Presenting the substance in a condensed form; concise: a summary review.
Performed speedily and without ceremony: summary justice; a summary rejection.
A presentation of the substance of a body of material in a condensed form or by reducing it to its main points; an abstract.
Of, intended for, or suggesting summer.
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.