When to use “in”, “on” and “at”

Question

I’m not a native speaker and I started English classes in school later than everyone else, so I started in 4th grade when everyone else has already 3 years of learning the basics, and since these are really basic words I never learned them in class

So, please, how do I know when to use each one? I can get by a bit as evidenced in this post, but a lot of times I get it wrong

In: Other

Answer 1

A tricky part of “on” vs “in” involves vehicles.

If you can easily stand up, use “on”. If you have to sit down, use “in”.   

You get “on” a large plane. But you get “in” a small plane.