This is not a fair comparison to compare petruchio’s behaviour  to Katherine’s at the beginning of the play because  petruchio was being insulting and how ever Katherina is just standing up for herself and being realistic .  Also she is different to the other girls in padua in a way that she is more independent and can twist words. but all she is trying to portray that  she does not want to get married.when petruchio has the argument with Katherina, petruchio said “, come, you wasp!” He is trying to insult her but when she reply’s “if I be waspish best be aware of my sting”. She uses what petruchio said against him in an intelligent way to stick up for herself but petrichio was trying to insult her. Also when petruchio is shouting at the servant Katherina was trying to calm petruchio down and you can see the behaviour that petruchio was showing to the slave and how different Katherina argues with people, she doesn’t show rage in her voice but she knows how to use words in a way that sounds like she is being insulting but she is really being truthfull and I believe this was  the difference between petruchio’s behaviour  and Katherina’s