The only person he actually trained was Sasuke. He didn't do jack kitten for Naruto or Sakura. And before people bring up the RS training, he only told Naruto how the shadow clones work and what Naruto's chakra nature was. Asuma taught Naruto more than Kakashi did during that.
Kakashi played favorites and completely ignored Naruto and Sakura.
There is a reason for this however. The reason was because he knew that Sasuke could leave to go for Orochimaru. Kakashi specifically focused on Sasuke for this reason. He applied the heaven seal in order to protect Sasuke, but also constantly reinforced the lesson he was trying to teach Sasuke. Not to give into his vengeance and grief and to move on and make a new life for himself with Sakura and Naruto.
Sasuke may still go over to Orochimaru's side but he understands Kakashi's lesson and still debates what he should do. But in the end he doesn't care that its wrong and accepts the consequences.
Naruto was loyal to the village unlike Sasuke and wasn't looking for revenge. And Kakashi still taught him how to use shadow clones as Exp boosters and not only what his element was but which technique he should use. Then he pointed him towards Asuma for more expert advice.
Sakura was always loyal to the leaf and frankly didn't want to become anything more than Sasuke's boyfriend for most of part 1 Part 2 comes around but by then she's kind of peaked. There's nothing that Kakashi can teach her really.
And before we cry favoritism let's not forget other aspects to being a teacher. Support, criticism, etc. Kakashi has that in spades taking care of both his students physical and emotional needs. examples: Telling Naruto to eat his vegetables, numerous times he's protected naruto and sakura, taking on Sakura's burden of killing Sasuke because she can't do it etc.
Edited by Shadow1275, 19 April 2015 - 12:59 AM.