Complex sentence: Feeling isolated and ridiculed, Jonathan nearly committed suicide near the end of his senior year, but changed his mind after speaking to Buffy, who had mistaken his presence in the campus' clock tower as a threat against the general populace ("Earshot").
Split into simpler sentences: Feeling isolated and ridiculed, Jonathan nearly committed suicide near the end of his senior year. He changed his mind after speaking to Buffy, who had mistaken his presence in the campus' clock tower as a threat against the general populace ("Earshot").