Two people are talking to each other, if you want to talk with them, let observe their body and feet; if they turned towards you but unchanged their feet, they really do not want you to participate in this conversation.

In the same way, if you are talking to someone (eg your colleagues) that you think they care what you say, check that they are rotated their body or twisted legs toward you; If their foot is not towards you, it is better quickly to end the conversation because they did not want to hear what you say.