As it turns out, week 3’s materials mostly include new vocabulary and grammar. It was my first time to learn the uses of “找，上，起，动 etc” in detail. I tried to understand it by reading a lot of example sentences but could not figure it out. I ended up re-learning those in 1:1 class. I still don’t completely understand but hope to master it by trying to use the grammar as often as possible and asking the native speaker to correct me.