Although children typically deepen their vocabulary knowledge in 2nd and 3rd grades as it relates to reading comprehension, development of vocabulary occurs at all ages. During early childhood, vocabulary is linked to language comprehension and understanding words heard. Upon entering school, as reading skills develop, so does vocabulary knowledge. By second and third grade, many children have mastered basic skills to decode, resulting in a shift to strengthen vocabulary.

A child demonstrates knowledge of the meaning of words by identifying and constructing definitions of words, and by using the words correctly in conversation.