However, a severely damaged CV joint *could* cause the symptoms you describe if the damage is so extensive it's preventing the driveshaft from turning. This would be unusual, though. Most often, a bad CV joint produces other symptoms like clicking or popping noises, especially when turning. The car might also vibrate excessively.
Since your car won't move even when giving it gas, the problem is more likely to be one of these:
* Transmission problems: This is the most likely culprit. A problem with the transmission itself (e.g., a broken linkage, internal failure, low fluid) would prevent the car from moving regardless of throttle position.
* Clutch problems (if manual transmission): A completely failed clutch would prevent power from reaching the wheels.
* Engine issues: While unlikely to completely prevent the engine from starting and idling, a significant engine problem could prevent enough power from being generated to move the car.
* Driveshaft problem (beyond the CV joint): A broken or severely damaged driveshaft could also prevent the car from moving.
You need to have the car inspected by a mechanic to diagnose the problem accurately. Focusing solely on the CV joint might lead to missing the real issue.
