Mr Koh is a very passionate tutor who will do his best to help each and everyone of his students. He is always patiently answering our queries and does his best to explain chemistry concepts in many different ways to make it easier for us to internalize them. He also exposes us to many different types of questions that are popular in exams to help us familiarize with them. He has helped me to improve my grades tremendously. Twig Learning Center is a great choice for anybody looking for a clear, concise and dedicated tutor.