In order to avoid the vice that he’s addressing, St John’s step on talkativeness is very short. I will follow his lead and simply provide you with a few things he says.

“Talkativeness is the throne of vainglory, on which it loves to show itself and make a display. Talkativeness is a sign of ignorance, a door to slander, an inducement to jesting, a servant of falsehood, the ruin of compunction, a creator and summoner of despondency, a precursor of sleep, the dissipation of recollection, the abolition of watchfulness, the cooling of ardour, the darkening of prayer.” (11:2).

He unpacks this statement further by simply saying:
“He who has become aware of his sins has controlled his tongue, but a talkative person has not yet come to know himself as he should” ¬†(11:4).

But this vice is one that is difficult to overcome:
“Few can restrain water without s dike; still fewer can tame an intemperate mouth” (11:12).

May God grant us His grace!