Q: The driver side door wont open even though its unlocked what part do I need to get to fix the problem?

Bought this car off a couple a few months back the driver side door originally opened, after my husband test drove it he shut the door and it no longer opened what could be causing it to not open? Its almost as if the door handle is broken it pulls out but you dont feel it pulling whatever it pulls to open it, like its one of those dont pay attention until it stops kind of things, i guess kind of like a regular door knob thats tongue is jammed inside except instead of being unable to close its unable to open. Do i need to buy a new door handle?
My car has an automatic transmission.