How can I speak more intelligently?

Answer 1

One thing too when speaking publicly, is to be comfortable with yourself and your thoughts that you share. When you exude confidence, poise, and your personality, your words will be ominous.

Answer 2

One thing I teach my public speaking students is to speak more deliberately. It takes time. It takes practice. (And a lot of knowledge on the subject you are speaking about!) Eliminating crutch words (uh, um, like, soo...) can also go a long way towards helping you speak more intelligently.