The contrast between form and function in language can be illustrated through a simple medical analogy. If doctors studied only a limited portion of the human system, such as anatomical form, they would be unable to adequately address their patient’s needs. To fully treat their patients, physicians must understand the purpose of the human body and the relationships between organs, cell, and genes. Similarly, ELLs need to understand both the form (structure) and the function (purpose) of the English language in order to reach higher levels of proficiency.