Sure, connect it to the car with jumper cables.
Jump it, it will either start or it wont
Certainly, a loose wire on the car battery can cause the car not to start.
Get a donor car and use it's battery to start your car. You will need a set of quality jumper cables. Or you can charge the dead battery on the car for about 2 hours with a good 10 amp battery charger.
Yes, if your car battery is the same voltage as the ATV battery.
A starter does drain a battery. The battery holds a charge so that you can use your starter to start the car. After the car is started the alternator recharges your battery and runs your car and all it's accessories. If your car won't start or is having a hard time starting you can drain your battery by repeated unsuccessful attempts to start it.
No, You do not need a key fob to start a car. When starting a car, you put the key in the ignition and turn. Power comes from car battery, not from the key fob battery!
if the battery is good and charged sure
You can get a new battery, you can jump start the car with jumper cables and another car with a charged battery. You can also put a battery charger on your battery to give it a charge.
Have the battery checked.
Weak battery and no gas can both cause a no start.Weak battery and no gas can both cause a no start.
If the other cells are still good, it's not too cold outside, and you don't have to crank it for long - then they usually will.
The car will then be unable to start.