Cooing: Around six months, babies start making noises. They shout, growl and coo. Babbling: Around 10 months of age, children start making more meaningful sounds. This is called the babbling stage. They usually start with repetitions of b and m. One word stage: Around 12 to 18 months, the children start speaking one word sentences. At this stage, children have an active vocabulary of 20 - 50 words. Two word stage: Till 24 months, children start speaking a two word sentences: "Mommy water", "Daddy look".