Need help translating a few sentences. Hello. I would like some corrections on the grammar of these sentences: 1. " il est le sorte de personne qui fut bêtement et tenir bon de son avis, peu importe de logique et si il s'est avérée erroné" I was trying to say "He is the type of person who would foolishly stand behind his opinions, regardless of logic and if he is proven wrong". I didn't know how say "foolishly stand behind" so instead I put "be foolish and stand behind". 2. "il a trouvé ses cours difficile et comme il manque de l'intelligence, il doit sa réussite à sa nature assidu et travailleur." I wanted to say "he found his classes and as he lacks intelligence, he owes his assiduous and hardworking nature". 3. "de depuis s'enfance" I wanted to say "from since his childhood"