In 2-5 Year Olds Language development varies considerably from child to child, even within the same family, during the ages 2 to 5.
Some preschoolers develop language skills at a steady rate.
Others master words in an uneven manner. Some children are talkative while others are quiet. Boys often start talking later than girls, but this evens out by school age. By the time the child turns 5, they have a 2,500 word vocabulary and complete sentences are usually spoken. Between 2 and 3 years, four and five word sentences are used.