In the class, we always say that Mandarin is easier to learn and more logic than English . But there are some Mandarin words and structure that are a bit hard to explain in English. This is one of the examples: In broken English, the sentence sounds like: 1. Before eating, need to wash hand 2. After eating, don't do exercise. Let us know in comment below whether you understand or not. We will try our best to explain. The best way is to practice and apply what you have learnt!