通常用to的情況：
(1)destination 目的地
We are going to Paris.
我們要去巴黎。
(2)Distance 距離
It is about ten meters from my house to the university.
從我的家到大學也就十米。
(3)Giving 給
I gave the book to Mumu for reading.
我把書給木木讀。

通常用for的情況：
(1)Benefits 影響（好處/壞處）
Yogurt is good for your stomach.
酸奶對你的胃好，
Too much sun light is bad for your skin.
曬太多太陽對你的皮膚不好。
(2)Period of time 時間段
I have been doing podcasts for 8 months now.
我已經錄了八個月節目了。
(3)Scheduling 安排
I made an appointment for the 30th of March.
我在三月三十號又個約會。
(4)Doing something to help someone 幫助
Could you carry these books for Mumu？
你可以幫木木搬這些書嗎？

我用這個枕頭枕著睡覺。
I am using this pillow for sleeping.
I am using this pillow to sleep.