PLS Help

I have 1997 Grand Marquise, when I start it, the starter will keep clicking, but the engine won't run? I checked the battery and it is ok. But sometimes it will run smoothly, but within few days it won't ? Can any help!
Thank you in advance

Check all the connections on the battery. These include the battery terminals, connections on the block, srtareter, solenoid, alternator. Thjese need to be clean and tight. Also, the battery needs to be properly tested for state of charge and current draw to be sure the battery will stay up.