Interview

If you have knowledge and no comm skills,you are bound to fail in an interview. On the other hand if you have good comm skills and no knowledge,then also you will fail. Hence a smart blend of both is required.

Communication does not necessarily mean communicating in English,if you can communicate your ideas well even in your mother tongue then that is also be acceptable. Communication skills means you can present your ideas coherently and with ample confidence to so as to leave no doubt in other person's mind that you are wrong. For improving upon this trait,first method is to participate in discussions with people having knowledge of the subject matter (eg your friends,classmates). Form a group,pick a topic periodically and have a friendly discussion. Secondly read a lot,apart from your books,that will broaden your view point. Here reading means newspapers,magazines and non fiction books. Third,read writeups related to your subject. For example- ASB's opinion which are regularly published in Journal and on website and form your own opinion on it. Last but not the least watch news channels discussion programs like "The Firm"on CNBC and notice how the speakers articulate their answers. 

Hope this helps.