My cl was dead when I tried to start it. I took the battery of my cl and put it on my Honda Civic. The Civic started right up. I let the Civic run for about ten minutes. I then but that battery back on the cl. The cl started right up.

Is it my starter or my alternator?

 

Answer; the starter is only used to start the car.. the alternator "charges" the battery.
go to autozone and have your alternator tested.