A 3 year old child can do all, except –
Eat with a spoon
Climb stairs running
Walk properly
Vocabulary of 20–100 words
Important milestones of a 3 years child

Rides tricycle                                                             
Stands momentarily on one foot.                           
Draws a circle.                                                            
Can dress or undress himself completely              
Builds tower of 10 cubes 
Knows his age and sex.      
Repeat a sentence of 6 syllables        
Has a vocabulary of 250 words.                 
Counts 3 objects correctly.    
Can withhold and postpone bowel movement.