That is a decent way of finding out whether the person is a native English speaker, actually.

This rarely happens to non-native speakers.

Weird. They're easy to distinguish from their intended uses... For me, it's always things like effect vs affect.

Add commas after "WHY" and "mistake". Change "it's" to question form "is it" or consider expanding the start like "Why do I find... it's..."

1/5 see me after class

Hack: if you see a ' at the word, thats two words(or more!) in a trenchcoat trying to fool you!

Split then, and read what you're trying to say with the words splitted

Example: You're splits to "you are", so the quote goes "Split then, and read what you are trying to say with the words splitted"

Your becomes this: Split then, and read what your trying to say with the words splitted

Your implies "hey, here is your phone", which isn't correct While "you are" implies you and a action that you are performing

Isn't is the same thing, splits to "is it not" (3 words! Devils)

As a non native I feel violated. It was always nessesary and recieve for me

Don't remember the last time I made that mistake.

I noticed that people will sometime's do this and I learned a bit about it and apparently some culture's do it, but it still doesn't make sense because the people in question do it without any discernable consistency or pattern