How we can increase our communication skills about sales?

The proof of the pudding is in eating. You can't learn swimming without entering the water. So books and classroom training are no doubt important to build a base. But actual knowledge comes from the field. And communication doesn't mean you have to be proficient in a particular language. 

Effective communication in sales comes from the field. And the golden rule here is - Listen more , talk less. Understand more , argue less. Learn from the filed and past mistakes and don't repeat them . :D