I am a Web developer and I am working with a relatively new company, I am hired part time because I'm a student. A few weeks ago the company hired another developer for full time that wants to do some changes and the bosses are green light about it. So here comes my problem. I asked him face to face what should I learn to be useful and he told me "X" would be good since it helps the project to be delivered faster and of course I started to get a hang on it and the bosses asked me how I was doing and what am I studying and I told them that I studied "X", because I talked with my co-worker and we agreed upon this. At that moment they asked him about this and he denied this and said that he never told me as such. How can I solve this issue without quitting or looking like I am at fault.