Heard him speak (hkousan autou lalounto). First active indicative of akouw and present active participle of lalew in genitive case agreeing with autou, object of akouw. "Heard him speaking" (kind of indirect discourse). John had disciples (maqhtai, learners, from manqanw, to learn). They followed Jesus (hkolouqhsan twi Ihsou). Associative instrumental case after verb (first aorist active indicative, ingressive aorist, of akolouqew). These two disciples of the Baptist (Andrew and John) took him at his word and acted on it. John the Baptist had predicted and portrayed the Messiah, had baptized him, had interpreted him, and now for the second time had identified him.