Should parents use motherese when speaking to their children and is it really necessary? Does it help the development of a language or not?
It’s completely natural for a mother to talk to her child with ‘babytalk’, or ‘motherese’, however many fathers don’t tend to change the way they talk, and will speak in the same tone to a child as they do to a friend or colleague. This is probably because it’s not very ‘manly’ or ‘cool’ to speak in a varied and high pitched voice, so ‘fatherese’ doesn’t really come naturally to them.
From a baby’s point of view, hearing a sing-song voice that varies in pitch and uses simple words is a lot more attractive and fun to listen to than a more serious, monotone voice that is saying longer sentences and using complicated words. So surely both parents should speak motherese to their child?
But maybe dads can be let off from not wanting to talk babytalk. It is now thought that the difference between the way each parent talks to their baby could be good for the child’s language development because whilst the mother talks in a more intimate way that is easier for the child to listen to, the adult-like way the father talks will get the child used to the outside world and get them more familiar with the grown-up way of speaking.
http://www.techtimes.com/articles/54047/20150519/motherese-fatherese-why-dads-don-t-baby-talk.htm
Introduction to Linguistics 