in是介词,一般只能作介词.
inside也做介词,和in的意思接近.
但是inside可以做名词.
名词 n.
1.内部,里面[C]
There is a label on the inside of the box.
盒子内侧有个标签.
2.(人行道、道路的)内侧[the S]
That car tried to pass me on the inside.
那辆汽车试图从道路的内侧超过我.
3.【俚】内幕,内情[the S]
He is on the inside of that deal.
他知道那笔交易的内幕.
4.【口】肚子,肠胃[P1]
I have a pain in my insides.
我肚子疼.