1. A portable machine for teaching students to read comprising: keyboard means having manually actuable switches at least some of which individually correspond to separate grammatical characteristics, display means for providing a visual display of words by generating images of words internally transmitted thereto in electronically encoded form, indicators of correctness and incorrectness, word set defining means for storing a multiplicity of words in electronically encoded form, and for assembling said words in sets wherein said sets are separately selected in response to separate actuation of said switch means corresponding to grammatical characteristics, random selection means connected to said word set defining means for selecting words at random from among words in a selected set and for transmitting words so selected to said display means for generation of an image containing at least one such word for visual observation, means for internally associating a particular one of said manually actuable switches with each of said displayed words, comparison means for sensing actuation of a manually selected switch and for ascertaining whether said selected switch is the switch internally associated with said image, and for providing an output indicative of the comparison results to said indicators of correctness and incorrectness.