Vocabulary refers to the words we need to know to communicate with each other.  The primary source of learning new words for younger children (up to age 5) is oral language experience.  They learn new words because they hear them (For the Love of Words, Paynter, Diane E. and Elena Bodrova, 2005).  They learn words common to their environment.  When they enter school, they still learn most words by hearing them.  They also move into more "book language" or academic language, which may be very different from their previous experiences.  By first grade, students learn more content words that are important in their classrooms.  They also begin to learn word parts (beginnings/prefixes and endings/suffixes).  They may categorize words (a desk as furniture), use synonyms (a dog as a puppy), or list functions ("something you eat with" for spoon) or attributes ("it is soft and has 4 legs" for puppy).  Second graders learn more prefixes, suffixes, and compound words, etc. to learn more words on their own. (For the Love of Words, Paynter, Diane E. and Elena Bodrova, 2005)

For all students, vocabulary instruction is important, but for lower socioeconomic students it is critical. First grade children from lower SES groups knew about 1/2 the words as their higher-SES counterparts knew in a prominent study by Graves & Slater, 1987. 

While many words are learned in context, direct instruction is necessary to begin to bridge the gap in our students' vocabularies and thereby enable them to be more successful.  Below is a Keynote presentation on Vocabulary that has been shared with teachers in previous years.

Vocabulary Keynote

Vocabulary Article