Some patterns are no problem at all, some are a pain and never look right. For instance, a feather and fan only takes a little thought and a choice of how you want the finished fabric to look, while knitted granny squares...heh, I know they're possible but they don't look right to me. Charted things done in single crochet translate pretty well, although you may want to play with the row count a little because knitting will look "squattier".
Of course, crochet enabler that I am, I'd say just grab the videos, a hook and some yarn and mess with them until it works for you. Not a whole lot in this world is actually impossible; some things are more difficult than others. Fortunately, crochet isn't one of those