I started my PhD 6 months ago and was extremely excited when I started, but I found out I was sharing my project with a new PostDoc. Since I started I have been doing very basic work. At first I thought this was normal.Recently I have really wanted to expand my work and my knowledge, and have discussed this with my supervisor and partner and have found out that every idea I have is already being put to practice by my partner. I have now realised Im not just doing these basis tasks bcoz Im still new, but bcoz I am not being given the chance to do anything else, as all the imp work is done my partner who is obviously better qualified and can get results quicker. I feel like there is no role for me and feel useless. On top of this I am worried about what will happen 2 years, will there be any work I have done myself for me to get a PhD out of.I am really interested in my topic but don't no if at this stage I am better off just getting out and starting another PhD in sep.

Part of the problem might be that the post doc IS new, they may still be in student mode and unable to let go of anything. You must ask them both, together or separately, when you will be getting your own little bit of the project, and what this is likely to be. You could say that you understand that your ideas so far have been taken over by them, perhaps because they can get the results more quickly, but now you have gained some experience in the area you really feel that you need to get on with something more substantial. If it is an area you are interested in, don't give up, there is probably a lot of other things you can be doing at the moment that you will find harder to fit in later, so treat it as anopportunity to get some basic groundwork in place so you have a suitable platform ready for when you have a bigger part in the work.

I think your concerns are valid and it's important that your PhD is your own project. My understanding is that there is a very definite limit to the colaboration allowed in a PHD. Certainly by the end of your first year you should know which bit you can carve off as your own. Lab projects tend to be colloborative - but your PhD should be an identifiable subproject. As long as that is the case - it doesn't matter whether many procedures are actually shared.

can you talk to the partner and split up the workload "officially"?