Identify a person's learning style as visual if you notice someone understanding a concept through the use of visual aids such as pictures, diagrams or videos. They also learn by observing body language. Visual learners usually need to see the process of a concept before they can really understand how or why it works.
Classify a person as an auditory learner if you observe a person who learns better listening to lectures, discussions and listening to tone and pitch. Auditory learners grasps thing easier when they are explained verbally and when they get a chance to talk things out.
Recognize a person who grasps concepts with a hands on style of learning as kinesthetic. Kinesthetic learners understand ideas better when they are fully involved and are actually performing the task or concept.