Only one of my grandparents was still alive by the time I was born - and she lived thousands of kilometres away.
My father was born in 1902, my mother in 1921. They were born into families in which speaking grammatically was natural and automatic - learned from the cradle and toddlerhood. They didn't so much "use" grammar as have it prerecorded in their neural connections so that it flowed without the need for conscious thought. It was a time when public primary school education included the rote learning of grammar, the terminology for types of words, how words function within a sentence, and how to parse. Dad was a journalist and novelist, among other things. Mum was a lifelong letter writer.
For my parents, especially Dad, correct grammar was not sufficient; it was just as important to pay attention to the subtleties of syntax, context and tone.
I took grammar for granted, until I was five, got to school, and discovered that it wasn't automatic for all the other kids. I had to learn how to intuit the intended meaning in incorrect grammar. I'm hoping this doesn't sound arrogant. It was just chance that I was born into these circumstances.
For myself - I don't always like proper grammar. It can sound too bookish, too stilted. Creative writers are now free to be very flexible, to break almost every rule as long as the meaning is still evident. Colloquial speak is so shot full of grammatic mistakes that we translate and come up with the right results without realising we're doing it. Our language, as it always has, is changing.
