I am not a native english speaker. However, I do consider myself close to a fluent speaker. I have even talked with americans. I talked with a therapist from America. She was surprised to see that I can speak fluently. I have learned english from reading books, articles, watching videos and movies, and practising with my phone. I have never focused on grammer. Lately, I have found that I make a modicum of grammer mistakes while writing and speaking. So, I have decided to improve upon it.

Most native speakers don't know basics of grammer and yet they speak fluently. They have learned it through real world experience. However, have you ever seen any individuals making grammer mistakes while speaking?