User blog comment:DoctorBleed/A Million Little Things of Bleach: On Rejection, Disappointment and Contests/@comment-24101790-20151122071028/@comment-5614678-20151122194833

You can go ahead and say "there's a difference between real life and writing" but if people in a story don't act and speak like real people it will most certainly detract from the story far more than any grammaratrical error or spelling mistake would.

You can't write a story where people talk like robots and expect the audience to just accept it because "it's a story." I would argue it's actually extremely important to make sure dialogue sounds natural and realistic, even when it would it incorrect by a dictionary standards.

Because human beings aren't dictionaries. They're human beings.