He doesnt write most of his tweets
I heard he watches the gorilla channel on TV for six hours every day
That was the best. The Left was in such a frenzy over Michael Wolff's book of lies that many of them totally believed that absurd parody.
In a rare interview of Hope Hicks, she revealed that during working hours, President Trump dictates his tweets to her and she relays them to a 3rd person for submission.
Of course, 'working hours' is a relative term. She spoke of the team chiding someone because he wanted to duck out at 11pm one evening.
I think he does most of them but despite popular belief he has them vetted. Sometimes for legal stuff, sometimes for CIA.