From birth to 3 months a child should began to recognize familiar voices and smile reflexively. A social smile should develop at around 3 months
From 4 to 6 months a child should begin to babble and use more consonant like sounds (p,b,m). They should move their eyes toward a source and begin to vocalize excitement and displeasure.
From 7-9 months a child should begin to play vocally, shout for attention, and begin using jargon (pre-linguistic vocalizations in which infants use adult like stress and intonation).
From 10-12 months the child should recognize their own name, use one or more words, and follow simple commands.