Car is turning over but will not start

What is your question?

I was pulling out of the drive way and the car shut off, I tried turning it back on and it turned over but would not start. I let it sit for 10 minutes and started it up again and it started right up but I heard a rapid knocking coming from either near the alternator or the center of the engine. Later that night I bought oil and the next day I changed my oil. Still had the rapid knocking but then it only happened when I let it sit at a light/stop sign. Later that night I was coming home from work and the car shut off and wouldn't start, had to push it home. Now everytime I start it, it will turn over but not start