twenty minute,twenty minutes,twenty minutes',与twenty-minute的用法有什么区别各相当于哪种词的用法?

1. twenty minute，无此一说；2. twenty minutes，“20分钟”；3. twenty minutes'，“20分钟的”；4. wenty-minute，也是“20分钟的”，和3意思相同。举例如下：
It takes me twenty minutes to get to the shop. 到那家商店要花我20分钟。
The railway station is twenty minutes' (或 wenty-minute) walk away from here.火车站离这里步行20分钟的路。

twenty minute 这种表达是错误的
twenty minutes 相当于名词
twenty minutes' 和 twenty-minute 是一样的 都相当于 形容词
例：It took me twenty minutes to go to school
It is twenty minutes' far from my home to school
It is twenty-minute far from my home to school

twenty minute没这个用法twenty minutes就是数词+可数名词复数twenty minutes' “20分钟的”相当于形容词,后面加名词,twenty-minute “20分钟的”相当于形容词,后面加名词,和twenty minutes' 可以想通