Hi Sanne!
First of all thanks to Harlan and Teresa for taking the time to answer your question, that's great!
In addition to what they have already said: Take a look at the site for answers to all your questions, the link is on the right side of our TripAdvisor page. Our tour guides are all local, speak fluent English and are very enthusiastic about their city. You stop 5 or 6 times for a bite to eat and a drink, and you get to see the many different faces of Rotterdam on the way! Please don't hesitate to contact us if you have any further questions, my number is +31617479420.
We hope to welcome you on one of our tours!
Best regards,
Paul.