In, on 和 Into and Onto

的差別在哪裡？如果不好說明，請提供一些例句。

"in" and "on" refer to relative positions inside and on top of something. They make NO reference to any movement from not being "in" or "on" something, to then being "in" or "on" that something.
"Into" and "onto" indicate a movement from not being "in" or "on" something to being "in" or "on" that something.
I jumped on the trampoline - I jumped up and down, and could have started jumping when I was already on the trampoline.
I jumped onto the trampoline - I was definitely not on the trampoline, jumped, and ended up on the trampoline.
The same is true for in and into.