I am not aware of there being anything unusual in Keats' use of this word - but if you think there might be, there is an excellent online concordance to the works.
It should be John Keats' or John Keats's.
Yes, John Keats did use rhyme and meter in his poetry.
There are two accepted forms for possessive singular nouns ending in s:Add an apostrophe (') after the existing s at the end of the word: Keats'Add an apostrophe s ('s) after the existing s at the end of the word: Keats'sExample:Keats' poetry is still quoted today.Keats's poetry is still quoted today.
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Robin Keats is 6'.
Caitlin Keats is 5' 9".
Ele Keats is 5' 7".
Kathryn Keats is 5' 8".
Zachary Keats is 6' 1".
Donald Keats was born in 1929.
Keats Petree died in 1997.
Keats Petree was born in 1919.