1. That won't work - how do you know until you've tried?
2. I can't do it - what can you do to be able to do it (training etc)?
3. Impossible - open your brain to how it might be possible.
4. That's not fair - life is not fair so look for ways to improve the situation.
5. It's not my fault - instead of focusing on blame focus on problem solving.
6. I might be able to - don't set yourself up for failure.
7. That's not my job - sometimes to help the team or yourself move up the ladder you need to do somethings outside your job description.
8. Need - your need food, water and shelter. Be careful how you use 'need' apart from those things.
9. I think... - it's wishy washy. Use I believe or I know instead.
10. I'll try - to quote Yoda, "Do, or do not. There is no try."