It's Not What You Say—It's How You Say It!
As a career coach, I spend a lot of time preparing clients for job and informational interviews - we video and analyze practice interviews designed explicitly for that role and organization.
Research has shown that 80% of communication is non-verbal - body language - communicating messages to the other person(s), even in virtual situations.
The key to successful interviews is preparedness - you cannot think up answers and focus on the 80% of communication that is non-verbal simultaneously. You end up losing eye contact and fidgeting.
A significant part of the verbal component is para-verbal - the messages conveyed by tone, pitch, and voice pace (speed) and deal with 'how' the messages are delivered rather than 'what.'
Pause for 3- 5 seconds to make sure you understand the question - what they are getting at - and your answer. If you need more time, say so. Do not say, "That is an interesting question". Short periods of "dead air" are acceptable.
Eye Contact. Looking directly at the person you're talking with helps communicate your sincerity and increase your message's directness. If you look down or away often, you present a lack of confidence or deference to the other person.
Body Posture. Research has shown that how you stand or sit is a huge part of how you come across—and even how you feel. While facing the other person directly, an active and erect posture lends additional assertiveness to your message. Keep two feet on the floor. Rest our forearms on the table - it will help to stabilize yourself. Steeple or interlace your fingers until you want to make a hand gesture. Sit still - challenging in a swivel chair. You may want to look at Amy Cuddy's Ted Talk on body language.
Gestures. Gestures go with posture to lend strength to your self-expression. Accentuating your message with appropriate gestures can add emphasis, openness, and warmth. While gesturing is culturally related, a relaxed use of gestures can add depth or power to your messages. However, remember you are not using sign language.
Facial Expression. Let your face say the same thing your words are saying. Your expression should agree with your message. A friendly communication should come with a smile. Get to know how your facial muscles feel in various expressions—relaxed, smiling, angry, questioning.
Fluency. A smooth flow of speech is a valuable asset to get your point across in any conversation. Clear and slow comments are more easily understood and powerful than rapid speech filled with long pauses and stammering.
Listening. Listening is an essential part of any conversation - see my post.