I’ve done that all my life. Writing and speaking are two different arts and people adjust each to the audience they are presenting to.
Heck I can use Hillary’s fake southern accent as a speaking example of the same. ;)
lol. I can write very well when I want to but speaking, I’m just a Staten Island gavone.
I can switch to Formal when in a meeting etc., but the natural way is the first.
What can ya do :)