e shopping（比如：我在购物 I am shopping；你或你们在购物 You are shopping；我们在购物 We are shopping；他们在购物 They are shopping；这些人都在购物 These people are all shopping；那些人都在购物 Those people are all shopping；他/她在购物 He/She is shopping）……
还有,在购物期间：during shopping……（比如：在购物期间,我经常喝水 I often drink water during shopping./ During shopping,I often drink water.；在购物期间,他经常喝水 He often drink water during shopping./ During shopping,he often drink water.）
我们今天不购物了.We will not go shopping today.
我不想购物了,我想回家.I don't want to buy things any more.I want to go home.
用法由语言环境决定.所以有很多不同的用法,你应该理解我局的几个例子了吧.
