Does "c'est normal que + " always take the subjunctive, or does it depend on the expression ? I have heard it used with and without, so I am just wondering if there is a rule. Merci par avance.
In my opinion, yes, the subjunctive is needed. I can't think of an expression without it.
"C'est normal qu'on fait/fera/faisait des fautes" : if you hear something like this, it's very bad French.
"C'est normal qu'on fasse des fautes" is correct.