How can i teach my two years daughter to say baba and mama? she knows the names of the shapes, letters, animals, & their sounds but she never call us

Keep saying them: Keep saying the words, or you and your spouse call each other baba and mama in front if her. I wonder if she calls you by your first name. That's fine. She will call you baba and mama as she gets older.

Developmental delay: It's impossible to make a diagnosis based upon the limited information you've given. However, if you check out http://www.Cms-kids.Com/families/early_steps/documents/growth_dev_chart.Pdf, you'll see that infants should learn to say mama & baba by about 12 months of age. It's not clear that she's otherwise talking but i would suggest an evaluation by a behavioral & developmental pediatrician.