Complex sentence: Service 19 is the flagship route running at a frequency of every 10 minutes from 7am to 7pm, with a 20 minutes on Sundays and every 30 minutes during evenings.
Split into simpler sentences: Service 19 is the flagship route running at a frequency of every 10 minutes from 7am to 7pm. It runs every 20 minutes on Sundays and every 30 minutes during evenings.