Can extensive knowledge of body language help you during negotiations?

i play my role as a diplomat during negotiation with delivering project or result to difficult stakeholder.i took them in confidence and relate it the situation which is best to the company or organization. 

Yes, Body language shows the confidence level of the person.

yes  because the body language of a person shows confidence level in negotiations and good communication more viable for negotiation

Actually yes, because most of the communication is done through non-verbal means rather than verbal ones. So, a manager or a leader should try to understand the body language in order to communicate well, but should not just focus on body language and leave the obvious message that is coming from someone's mouth. 

Yes, in many different ways.

Yes of course body language works for helping negotiations. And body language is one of the important things for communication.

Off course yes,  the extensiveness of body language will help during the negotiation. 

Yes body language helps in negotiations.apart from verbal communication body language can also pass or send a message across.

Yes it does. For effective communication, body language and usage of tone matters a lot. Each and every move get added to the final solution or the conclusion

Obviously yes, Body language helps a lot in Negotiation.