Speaking clearly is within your control. Nervousness and habit are the culprits if you find that you do not speak clearly. Now unclench it, relax it by moving it up and down a few times and say the same sentence again, moving your relaxed mouth and jaw freely. You should be able to hear the difference. This is not true.
Pauses are a vital element of non-verbal communication and are essential for a strong delivery.
They assist comprehension by giving the listeners time to think and absorb. They create emphasis when placed in the middle of a phrase or sentence. Often this is not the case as bad diction habits or past environmental factors can be the cause. Diction and pronunciation problems can be corrected by practising good diction habits or receiving instruction from a qualified speech instructor. Vocabulary can be built up quickly by keeping a lookout for new words and practising them.