Complex sentence: Trains run every 15 minutes during the day and every 30 minutes after 7:30pm on Mondays to Saturdays, the trains runs every 30 minutes on Sundays.
Split into simpler sentences: Trains run every 15 minutes during the day and every 30 minutes after 7:30pm on Mondays to Saturdays. The trains runs every 30 minutes on Sundays.