Your baby is 20 month and is fast approaching his two year old milestone. He is now much stronger than before and especially his limbs are working with more vigor. Your baby should be walking fine now, and running without much hassle.
What you need to know
Your baby's legs and the fingers are strong now, and has a firm grip. He is now able to throw his leg in the air and kick things around.
He will be particularly interested in doing this because now he will be able to move things around with his kick and hit. Give him a ball and you should watch him rolling it from one place to another rather conveniently.
However, if you feel that your baby is still not there, please see a doctor and get it checked for any deficiency in the body.