My Granddaughter Is 22 Months Old. She Does Not Talk

My granddaughter is 22 months old. She does not talk in words or short phrases. She cries sometimes when she wants something not incessantly. However, she does understand a lot of things. She laughs, hugs, and makes faces when she doesn't want to do something or doesn't like something. My husband and I are very concerned because she doesn't speak.