Babysitter gesucht für die Kinderbetreuung in Berlin

I am looking for a sitter for my four-year old son, ideally an English (close to) native speaker. We speak both German and English at home, but since he gets exposure to German at daycare, it would be great to have a little more English as well. I am looking for 1-2 times a week, usually a few hours during the weekend and a few during the week. My son loves to draw, and to build elevators, trains and water fountains with Lego. He is also very excited about subway rides.