Sephira is correct, as always :). Disclaimer: I learned all of this when I made a left turn and was hit by another car.
The identifiers as to who is at fault depends on which part of one car hit another. If the damage on your car, making a left, is on your backseat door or further behind it shows you were in the process of making the left when you were hit and as such is the other driver's fault. if the damage to your car is anywhere on the hood or front seat passenger door it would be considered your fault. Speed, weather conditions, whether either driver was on the phone or worse, texting, also must be factored in as identifiers as to who is at fault as well.
It would depend on the circumstances that led to the accident and who is to blame. It could be you weren't careful when turning to the left side of where you were seated. There are many factors which have to be considered and this will determine who is at fault in the accident. It is also possible the owner of the car did not check before driving in and you can have an officer determine who is to blame.
Without knowing all the facts, it's hard to say for sure, but the following would basically be true, depending on the exact circumstances.
If you are turning left, generally that means that you are the one that is cutting across the on-coming traffic, so if you were hit on the passenger side, by an on-coming car, the accident is likely your fault. However if you were hit from behind while you were stopped waiting to turn, and you had your turn signal on, then it would be the fault of the driver that hit you.