On my 96 civic, whenever i hit the lock button the lock tab only moves slightly but my passenger door locks. What could this be.

 

does this happen when the drivers door is open

 

all the time... when closed and open

 

It's supposed to do it when the door is opened. It's a safety feature to keep you from locking your keys in the car. Hold the door handle on the inside open in order to have it properly lock.

If it's not that then there's a chance one of the bars within the door is bent.