When you are cross-examining a witness, you should be careful not to give the witness an opportunity to explain. This is exactly what you'll do, however, if you use adjectives needlessly--
Q. "You couldn't see the collision clearly, Mr. Witness, could you?"
A. "Yes, I could. I had a very clear view of the collision. I was standing right there when it happened--there no way I could have had a better view."
The witness might also reply, "It depends on what you mean by 'clearly.'" In either case, the witness is no longer under your control, and the jury is watching him, not you.
Rather than using adjectives, think about the facts that together can stand in place of the adjective, then turn each of these facts into a separate question. It will make your point as clear as possible, will give the jury a visual image, and will keep the witness under your control--