It depends on the individual. Hopefully, you have spent enough time around the person to know his/her mannerisms.
Some people have mastered the skill of lying so that it is almost impossible to tell whether they are lying or being truthful. In that case, hopefully you know the truth, and if you do; stick to it, regardless of what the other person may or may not be saying or doing to convince you of otherwise.
Others, when they lie, if it's not in their nature;(beginner's level) they may fidget, their eyes may become shifty, they may begin perspiring, and/or their voice may quiver.
Others who are intermediate level liars may become defensive, or they may become overly sweet and kind--doing things for you that they normally would not.
There is no one size fit all sure sign for everyone. Knowing the person helps to know whether they are lying or not.