How to know when people are lying to you?

For example you ask your husband Are you going to work? Look at his eyes .
If he starts to look to the left then to the right very  quickly then maybe again to the right and he answers yes. He is lying he iss NOT going to work he has other plans.
He has already made plans.That's why he is looking to the left and right he he consulted himself

Do you want to know whether someone is lying to you?

Ask a question: Did you smoke  ? But ask him many times for example 5 times.
While asking look directly at him if he doesn't blink and he keeps looking into your eyes not to the left  or to the right  while answering then YES he is lying to you  if he blinks then heis telling you the truth.