As we process language -- both aural and written -- we make use of whatever contextual clues are available to make sense of what we hear and read. Visual information becomes particularly useful when it comes to trying to understand a new language. Language teachers have long known the value of gestures, pictures and realia (authentic cultural objects). Students can make use of visual information provided to process words and sentences that are new or partially new. Visual reinforcement can assist the learner in comprehending and internalizing what might be otherwise inaccessible.
Simple movements like pointing, nodding, and miming can illustrate ideas as simple as "It's over there." to ideas as complex as "You need to measure the shorter ones." Pictures and objects can demonstrate relationships as simple as the match of word and image, and as complex as the ethos of nineteenth-century sweat shops. Incorporating as much visual assistance into the ESL learner's activities, encounters and environment greatly enhances his or her ability to comprehend and acquire language in the classroom.