As the one who questions your expert on direct, you are the conduit through which your expert's opinions should be channeled before being delivered to the jury. Plan to deliver your expert's opinions in small, understandable pieces. Ask the expert to define, then to explain, any difficult words, meaning any words that you wouldn't expect to hear on a television soap opera. Build on what has come before, but don't plow ahead until you've established a solid base. Watch the jury for signs of understanding. If you don't see any, back up.