Complex sentence: The main event is the exchange of gifts between sweethearts, loved ones and respected ones--historically, men gave their girlfriends and wives roses, and women gave their boyfriends and husbands a book to celebrate the occasion.
Split into simpler sentences: The main event is the exchange of gifts between sweethearts, loved ones and respected ones. Historically, men gave their girlfriends and wives roses, and women gave their boyfriends and husbands a book to celebrate the occasion.