Ins and Outs of Completing Forms

A few days ago, I was formatting a form for presenters to provide information about their presentations at a workshop. It occurred to me that “to fill in a form” and “to fill out a form” mean essentially the same thing. Dictionaries prefer “fill out,” but the well-established phrase “fill in the blanks” inevitably, I think, leads to the phrase “fill in a form.” The “fill in” usage emphasizes placing information in particular places, whereas “filling out” emphasizes expansion to a completed state of the form (analogous to saying that a child’s face or figure “filled out” and related to the idea of “completing a form”). No doubt, the equivalence (or near equivalence) of “to fill in” and “to fill out”—a seemingly paradoxical state of affairs—results from these phrases having originated in different takes on the process of using a form. Curiously, we never speaking of “filling a form.”