Here are some developmental milestones to look for:
By the age of 18-24 months your child should be able to walk, build a tower of four blocks or more, say 15 words or more, and recognize names of familiar people, objects and body parts.
By the age of 24-36 months your child should be able to climb well, turn book pages one at a time, and recognize and identify almost all common objects and pictures.
By the age of 3-4 years your child should be able to kick and throw a ball, use scissors, draw circles and squares, speak in sentences of 5-6 words, tell stories, and can correctly name some colors.
By the age of 4-5 years your child should be able to swing and climb, print some letters, dress independently, recall parts of a story, count 10 or more objects, wants to please and be with friends, likes to sign, dance and act.