"dasha was raised in an orphanage in russia. although she is now 12 years old and living with her adoptive family in england, her speech is very delayed and she has problems with grammar. this indicates that she was not encouraged to talk between the ages of a sensitive period for language."

1 and 3 years

Explanation:

The sensitive period for language starts from the age of seven months to 2.5-3 years of age. By the age of three, a child ideally starts speaking of 2-3 word sentences. The prenatal influence on the child's language development is very important, as the initial phase of a child's life demonstrates how the child is going to develop his or her skills later on in life. In this period only the growth of vocabulary occurs. In the first few years of life language develops readily and after that language acquisition is difficult as well as less successful.