Which of the following is NOT a way we communicate non-verbally?

Non-verbal communication encompasses various forms that convey messages without the use of spoken or written words. The option referring to "words" is not a method of non-verbal communication because it relies explicitly on verbal language to convey meaning. In contrast, expression, volume, and gestures are all significant aspects of non-verbal communication.

Expressions, such as facial expressions, can reveal emotions and reactions without any words being spoken. Volume pertains to the tone and intensity of spoken communication, which can convey feelings and attitudes, but it is still fundamentally linked to verbal communication. Gestures include hand movements and body language that can emphasize or complement what is being said, creating a more nuanced communication experience. All together, these elements form a crucial part of how individuals convey and interpret messages beyond mere words.