This comprises both what is understood and what is expressed. Language development progresses from babbling to first words by approximately age one year, to a vocabulary of approximately 150 to 500 words by age two and a half. By age 2 and a half years, children begin to produce 2-3 word sentences such as "Daddy go", and "Me want juice". Children who have difficulty expressing themselves often become frustrated, and behavioral issues are common. If you suspect that your child has a delay in language skills, seek a clinical evaluation as soon as possible.