Readers vary in the linguistic, cognitive, and affective characteristics they bring to text. With respect to linguistic competence, they bring different levels of knowledge of word meanings (vocabulary) and syntactic awareness (grammar). With respect to cognitive competence, readers vary in their memory and attention skills, their ability to make inferences, their knowledge of text structures, and their capacity to draw upon real-world experience (i.e., prior knowledge). They also bring different levels of skills in the fluent identification of words in text. With respect to affective characteristics, readers vary in their attitudes toward reading and their motivation and engagement with particular genre and topics.