A little while ago you were in a crowded room and made a study of the persons disposed to silence.  But your study was carried on under difficulties, for many of those about you showed a tendency to copious or excessive speech.  One woman entered readily into conversation with you and convinced you that her natural disposition was to converse a great deal.  She was talkative.  From her you escaped to a man who soon proved that he talked too much and could run on with an incessant flow of words, perhaps employing many of them where a few would have sufficed.  He was loquacious.  The two of you were joined by an old gentleman who forthwith began to talk wordily, tediously, continuously, with needless repetitions and in tiresome detail; you suspected that he had suffered a mental decline from age, and that he might be excessively fond, in season and out of season, of talking about himself and his opinions.  He was garrulous.  You broke away from these two and fell into the hands of a much more agreeable interlocutor.  He talked with a ready, easy command of words, so that his discourse flowed smoothly.  He was fluent.  He introduced you to a lady whose speech possessed smoothness and ease in too great degree; it fairly rolled along, as a hoop does downhill.  The lady was voluble.  Into your triangular group broke a newcomer whose speech had in it a flippant, or at least a superficially clever, fluency.  He was glib.  Leaving these three to fight (or talk) it out as best they might, you grabbed your hat and hurried outside for a fresh whiff of air.

Assignment for further discrimination:  chattering, long-winded, prolix, wordy, verbose.

Sentences:  The insurance agent was so ____ a talker that I was
soothed into sleepiness by his voice.  The ____ old man could talk forever
about the happenings of his boyhood.  Through ____ descriptions of life in
the city the dapper summer boarder entranced the simple country girl.  I
met a ____ fellow on the train, and we had a long conversation.  She was so
____ that I spent half the afternoon with her and learned nothing.

Weak, debilitated, feeble, infirm, decrepit, impotent.

Weak is the general word for that which is deficient in strength. Debilitated is used of physical weakness, in most instances brought on by excesses and abuses. Feeble denotes decided or extreme weakness, which may excite pity or contempt. Infirm is applied to a person whose weakness or feebleness is due to age. Decrepit is used in reference to a person broken down or worn out by infirmities, age, or sickness. Impotent implies such loss or lack of strength or vitality as to render ineffective or helpless.

Assignment for further discrimination:  enervated, languid, frail.