when im sparing with my friends, every time i throw a straight left my arm clicks why?

I had a similar problem. The way I resolved it was by doing numerous stretches before sparring. For example raise your right hand to your left side while putting your left hand next to your arm pit not under it. And the same for your left hand. Their are more ways to stretch you can look them up on google or somewhere. Also doing 5-10 push ups 10 min. before sparring is also a good idea as it will bot affect you since its not that much and it will warm you up.

That is normal and happens in many people. It's just the joint in your arm and you cannot stop this.There is nothing wrong and no problem...

Maybe you have loose joints that connect your bones, and muscles. I mean if it's not painful then you shouldn't worry about it.