Could I built iphone apps using C language and how?

Could I built iphone apps using C language and how?!

No, you can't.

The reason is not technical but it's down to you. You asked the same question repeatedly over the last couple of hours. People have pointed you to where you can learn to program in C. You haven't gone through them yet simply because it takes far longer than a few minutes.

If that's all the time you are willing to invest in this forget the whole idea now because you will never learn C. It's an advanced skill and learning to program takes hundreds of hours, not two minutes.