I'm building an H bridge and I'm stuck at some point
The 10k resistors are doing not a lot because they are weak compared to the 1k resistors. So, when both switches are open the junctions of the 1k resistors are held at mid-supply, all the transistors are on and you have a shoot through situation. 

Now close a switch and that side of the motor will be pulled to Vcc but both the transistors are still switched on on the other side of the bridge.

This circuit uses emitter followers instead of common emitter configuration in order to avoid shoot through.



Disadvantage of the transistors being driven in emitter follower mode is that there is more voltage dropped across them than in common emitter mode necessitating more heat sinking.