动词不定式做后置定语,用来表示目的或用途.
fridge to keep food in 用来放食物的冰箱那这一句中的to 呢？That is to say ,you won't have much free time.这是个固定搭配 非要严格来说的话，to say在这里做表语的。 像这样的固定搭配或短语，记下来，会用就好。不必深究。