We have to come some sort of agreement about what we are going to talk about. Conversation involves an immediate response . There is not much of a time lag between the action of one person and the response of the other. This means, for example, that what we say may be less thought out. Linked to this is the need for us to be tolerant of what is said to us in the heat of the moment.
Conversation entails certain commitments.
For it to work, we have to trust in the others involved. When they say they will do something, for example, then we tend to have to take it at face value. At a minimum we have to be open to the possible truth of their words. Conversation involves interpretation - and in filling the gaps . To make sense of what others are saying we often have to make leaps forward.