Sight words are very important for your child to master because, believe it or not, “sight words account for up to 75% of the words used in beginning children’s printed material”, according to Study to Identify High-Frequency Words in Printed Materials, by D.J. Kear & M.A. Gladhart. There are different sight words for every grade level. Each set of words builds upon the other, meaning that once your child learns the sight words in Kindergarten, he will be expected to still recognize those words as he learns new words in first grade, and so forth.