The earliest clue may be a delay in speaking. Children generally say their first words at around twelve months of age and begin producing phrases by eighteen months to two years. Children who are vulnerable to reading and other academic difficulties may have a delay in reaching these milestones.

Once a child begins to speak, difficulties with articulation (pronunciation of sounds) may continue past the usual time. By the age of three and a half to four, children should be able to produce the sounds p, m, h, n, w, b, k, g, d, f, and y and produce the ending sounds of most words. By this age, a stranger should be able to understand a child’s speech. By the age of five or six, children should be able to produce most sounds correctly.

Other clues in the preschool years to possible future academic problems may be one or more of the following:
 
-trouble learning common nursery rhymes such as “Humpty Dumpty”
-little enjoyment of nursery rhymes and other rhyming books
-limited vocabulary and shorter utterances than peers
-difficulty putting thoughts into words
-very quiet among peers
-difficulty attending to task 
-trouble learning spatial concepts such as “first”, “last” and “before”
-frequent difficulty producing multi-syllabic words (e.g., “aminal” for “animal”, “bisghetti" for "spaghetti")
-difficulty learning and remembering the names of letters and/or colors
-trouble learning the letters of his own name
-difficulty counting and learning numbers
-trouble using scissors, crayons and paint
-reacting too much or too little to touch
-difficulty listening and following directions
-history of frequent ear infections
-a history of speech, language, reading or learning problems in parents or siblings