[randomcarbloke]

agreed, non-native speakers see the rules where native speakers do not.

[liquidk]

I suspect this is a bit of a generalization. While learning and seeing the rules is an essential part of bootstrapping the learning os a new language, at some point for both efficiency and style, it'll become second nature and awareness of the rules fades away almost as necessity.

[red-iron-pine]

Or put another way, the native speakers have learned to stop following the formal rules and fall into slang, regional dialects, etc.

The non-native speakers only have experience with the more formal approaches. Over time you can see them pick up the local idioms.