You can chat with them by messaging. Also there is always Skype that will allow you to talk with them with a web cam.

If you mean, how do you find a person to communicate with (as oppose to what means are available to communicate with them), then go to the Community tab at the top of this page and from the drop down choose language partners. From there you an look for a native English speaker who is learning arabic. Send them a message and arrange to be language partners - then it is up to you whether you Skype or use some other form of communication. Good luck - having a language partner is a great way to learn.