It is normal. Slowly and surely your little one will be able to say those words. Keep on saying all the different words and new words,eventually they will pick out. Sometimes they require time. No rush on it. Unless, they cant speak at all like merely no clear words you can hear (more to blabberring or pin pointing only) I have a friend, her daughter doesn't speak much and quiet until she goes to CC at 3 years old then she talk a lot and pick up new words/skills.