The language we speak.
What should be said, what should be left unsaid.
What is appropriate “small talk”.
Whom we should speak to, whom we should not speak to.
Whether communication should be direct or indirect.
How much emotion should be expressed.
Whether conversation should be formal or informal – and where.
The meaning of facial expressions.
The meaning of hand gestures.
The meaning of nonverbal communication.
How often we smile, whom we smile at, and the meaning of a smile.