My DS didn't walk till he was 19 months. He did everything late, first he rolled everywher for what seemed forever, he then commando crawled at 11 months, and then properly on hands and knees at 14 months. He pretty much stood up shortly after that but hung onto walls and furniture for again what seemed forever, and then he found the courage to let go and walked all by himself for like a few days before he started running and hasn't stopped since