"The car is dirty."
I know that 가 is a subject marking particle and 차 means car, and I am fairly sure that 자동 means automatic, however, I was wondering if every time you say car you have to use 자동차? I understand using it when you want to point out that a car is an automatic, however in this sentence that isn't the case so I am a bit confused. Thanks :)
I think the major difference is how formal you want to sound. In a more formal setting, you'd probably use 자동차, while in a less formal conversation you'd be alright to use 차
I'm korean and I use both 자동차 and 차 without difference. But 차 is more used because it is short