that printed words are not an arbitrary sequence of letters to be memorized, but that letters represent a limited number of speech sounds that combine to form spoken words. Young children do not intuitively grasp this principle nor do they think of spoken words as having any dimension other than meaning. Phonological awareness refers to children's conscious awareness of the fact that spoken words are composed of identifiable units including syllables, rimes, and sounds (phonemes). It also refers to children's ability to manipulate (segment, blend, substitute) those sound units.