Some examples of positive reinforcement:

• When I help around the house, I get praise, cookies, etc. from Mom.
• When I waitress, I try to be really pleasant and helpful, since in the past when I have been that way, I've gotten bigger tips.
• If I didn't show up for swimming practice, I couldn't swim in the meet. (Again, this is one where you need to look for the observable relationships--going to practice is reinforced by being able to swim in meets.)

Some examples of negative reinforcement:

• When there is a high pollen count outside, I take an anti-histamine a couple of hours befor going outside.
• My room condition report is due Friday, otherwise I'll be fined. I sent it in, eliminating the threat of the fine. (This one is a little more complex than simple avoidance, though. Can you see where the complexity is?)
• Not wearing my nametag at work gets punished by being fined. so I always wear my name tag. (This one is also fairly complex. I'm calling it positive reinforcement since the most direct connection of observable events is:
  wear nametag get full pay.

Some examples of positive punishment:

• An alcoholic, taking the drug antabuse, gets violently ill when he drinks alcohol.
• I avoid talking about anything controversial with my pig-headed roommate, since I know he will have a highly opinionated comment. (Discussing things with roommate produces an aversive discussion. Note the informal use of the term avoidance here is contrary to the more precise usage of behaviorists.)

Some examples of negative punishment:

• One night when I was driving to a party, I backed into a mailbox, and it cost me $450 to get my car fixed.
• When I was younger, I yelled at my Mom, and got grounded.