Hi all, my baby boy is 1.5 yr old. He doesn't speak a single word

Aisa nai h ku usne kbhi nai bola kbhi kbhi bol deta hai muma papa dada nana. Babbling pure time krta rehta h. Par kuch bolta nai. Bht koshish krti hu papa papa bulvane ku but no response. Mai story books bhi read krti hu uske sath. Samjhta sab jai instruction sab follow krta h. But bolta nai. Plz help how to make him sleep