French language Q&A Forum

Pouquoi "de" il essaie de parler français

The question read, How do you say, “We don’t know you at all.” Before I clicked on the drop-down arrow, I was expecting to see: Nous ne vous connaissons pas du tout. I was surprised to see that the choices only included the familiar form: Nous ne te connaissons pas du tout. Wouldn’t the fact that the familiar form was used imply that we do know you?  Is it that I was applying a literal meaning to a figurative question?

Je ne comprends pas le temps que ca lui prend de se preparer ! Is an example given to illustrate when l'indicatif is used and not le subjonctif. That I understand but I find the the sentence interesting and would like to ask :  1. Could  que ca lui  be replaced by qu'elle prend ?  and  2. Could que ca be replaced by celui que ?