My baby is 14 months old (13 months corrected). He was one month preterm. Can crawl, stand with support, pull himself up to  standing position holding everything. He can cruise as well however not started independent walking. Is this normal? He claps, waves hand as well. He says baba mama tata dada.. can understand commands like show me your hair, nose, tongue. He says "jaah", gagi (car) but not always. Are all these signs of normal development or is there any delay?