Since, having good grammar back ground is the added advantage for speaking, yet, speaking is the process of communication with others and expressing your desires, likes etal to others in the real sense..
better purchase audio CDs for communication, go to you tube and you can get more about communication and speech by good authors please download it and practice.. the best thing is stand before the mirror and speak at your will sure, this will develop a lot, also speak with your friends...
best of luck ....