The first unit of language of which young readers need to be aware is the word. Distinguishing words in speech is not a simple matter, because speech usually comes to us all run together. We more often hear someone say "Whuzapnin?" than "What is happening?" Once children are aware that language comes in word units, they can "track along" with print, by matching the words in their minds with the words on the page.

Most children begin to develop a solid concept of word in later kindergarten and early first grade (Morris and Slavin, 2002). But it helps if they have early experiences that call attention to individual words—especially since this can be done playfully and naturally (see below).

Not being aware of words in speech puts children at a disadvantage when they are learning to read. Suppose a teacher teaches the children the song "The Corner Grocery Store" and writes the words on chart paper. The teacher then asks the children to look at the printed words as they sing them from memory. A child who is aware of word units—who has a concept of word—can look at the word "corner" at just the instant she sings it. A child who does not have the concept of word may scan her eyes across a whole line of text as she sings the word "corner." Or she may look at only a single letter. In either case, at the conclusion of the activity, a child who lacks the concept of word is unlikely to have learned to recognize any new words from it. The child who had the concept of word, who looked at the written words just at the instant she sang each word, will have been in a position to associate the written version of the words with the spoken versions, and is likely to learn to read several of them from the activity.