Comparative form of chatty: more chatty(adjective)
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Use "chattier" in a sentence
"In a three-hour private training session last week, Banks was advised to change his shirts, talk more often about his tough childhood and be "chattier" if he wants to win the super-mayoralty in October."
"And the more he sucked on the cigarette the chattier he became."
"Their voices would be clipped Received Pronunciation, quite different from chattier tone of current Radio 4 announcers."