The superlative of fashionable is "most fashionable."
most fashionable
I am fashionable.
yes very fashionable.
That is a very fashionable hat!
Fashionable Nonsense was created in 1997.
Fashionable Lectures was created in 1872.
They're not fashionable now.
Comparative: more fashionable Superlative: most fashionable
the most fashionable company is totally north face
"I love Kathryn's style, she's always very fashionable."
The root word for "fashionable" is "fashion."