Complex sentence: After Tre gets involved in a fight at school, his teacher calls Reva and informs her that although Tre is rather intelligent, he is immature, aggressive, and lacks respect for classmates and adults alike.
Split into simpler sentences: After Tre gets involved in a fight at school, his teacher calls Reva. The teacher informs Reva that although Tre is rather intelligent, he is immature, aggressive and lacks respect for classmates and adults alike.