I suggest going with the benefit of the doubt (something I’ve referenced in It’s Not Fair!). Maybe their attitude isn’t sunny and they are a grouch to be around, but you really don’t know if this person is going through a divorce or has a seriously ill relative. Have they always been ill-tempered? Is it just toward you? If the answer is that they used to be positive Polly and they just haven’t been lately, then I suggest waiting it out. If the person is negative only toward you, try to address it.
Sometimes saying, “I know we have to work on project X together for the next few months. I’m excited to combine our talents and eager to get started.” This could help diffuse the situation and reiterate that you trust the person’s ability to help get the project done.
Just because you don’t want to hang out with this person after work and wouldn’t think of going to lunch with them, doesn’t mean you can’t have a working relationship. In a team environment, your success is your partner’s success and your failure is their failure. As long as everyone can remember that, you should be able to make any pairing work.
Focusing on the positive attributes even the most negative co-worker brings to the table can help get you in the right mindset. You could say, yes, she’s brutally blunt, but she’s very detail orientated and great at making a timeline based task list. Or sure, he monopolizes the conversation and asks the same question every single day, but he means well and is just trying to make sure you know he cares.
Obviously, getting a good read on the person is a great way to find that silver lining. Is he a control centered person? Let him be the one to suggest the starting point. Do you see her as scattered? Maybe she’s just able to multi-task extremely well or is very creative. Try to see the bright side.
If it does become a huge issue and you two can’t get past it talk to your supervisor (if you are comfortable). Reiterate that you are excited about the project and want to make it work, but you are having a hard time getting on the same page with Suzy. Just make sure you indicate you want to move past this issue.