My baby is 20 months old he knows how to say mumma but does not recognised me as mumma is it normal??

A. No mam please recognise very well who is the who are their parents whose mamma and whose papa if your child is unable to recognise it it is not good so what do you need to do is to teach a child properly who is the mother when you say Mama I am Mama towards me so that is how you can teach better