Learners often ask if Native Speakers make mistakes in their English. Of course they do!
People who speak English as a first language still make many spelling mistakes, but fewer mistakes in grammar. However, here are two very common mistakes made by native speakers:
We better go.
It should be 'we'd better go', but the 'had' often doesn't get pronounced at all, even in writing.
We should of left earlier.
It should be 'We should have left earlier.' But when people write it out, they follow the way it sounds to them instead of the correct form!
So there it is. The big question is whether it is okay for language learners to make these kinds of mistakes just because native speakers do, or if they should go for perfect English!