During a job interview, it is more often how you come across than what exactly you say. 

Are you likable?  Are you competent?  Are you a good communicator?  Is the light on in your head? 

Ok, here comes the importance of body language, a technique taught by the CIA in interviewing “friendlies” no less. 

Occasionally, nod your head forward and backwards. 

It says, “I understand.  I trust you.  I am on board.” 

It is like magic.  If you sit there like an unreadable sphinx, no job will likely be in the offing.