3-6 months
gains head and neck control
ability to sit
6-9 months
sits steadily
rolls over
can crawl on all fours
pulls themselves to a standing position on furniture
9-12 months
can use fine motor control
and pick up small objects
progresses towards un-assissted walking
15 months
most can walk unassisted
18 months
most can run
2 years
most can jump
3 years
most can stack blocks, do puzzles, and dress themselves
4 years
negotiate stairs, hop on one foot, walk backwards
5 years
skip, jump rope, jump off heights of several steps, able to manipulate writing materials