A baby boy staed speaking sentences of few words. What will be his age?

Usually by age of 1 year, a child can use 2 words (on his own jargon) with meaning for objects of daily use. His vocabulary increases during the second year. He uses 6-20 words by the age of 18 months. Between the age of 21-24 months, he makes simple sentences using two or three nouns without the use of verbs. He uses pronouns by 2 years and has a fairly good vocabulary of about 250 words when he is 3 years old. He can give a coherent account of recent experiences and events by the age of 4 years. Ref: Ghai essential pediatrics, 6th edition, Page 47 ; Nelson Textbook of Paediatrics, 17th edition, Page 1874