The distinction of "foreground versus background" in narrative discourse is fundamental, if not universal, to the literatures of the world. In languages such as Greek, this distinction is indicated mainly by means of tense-aspect morphology. The purpose of this article is to explore the types of situations in which the imperfect indicative occurs in narrative discourse in the Gospel of John; that is, to investigate, describe and possibly explain its function in those situations. The research is restricted mainly to narrative proper, meaning the main storyline and offline information, and does not include direct, indirect and authorial discourse as such. The findings are that the imperfect is the primary, though not exclusive, tense-form used to provide background information for events (etc.) in the main storyline, which is carried by the aorist indicative and historical present. The function of backgrounding is related to the imperfect's aspect and its characteristic linking with another verbal utterance, which also enables it to establish cohesion in a narrative. Background is provided in a number of ways, including setting the scene, giving background details, and indicating explanation, reason, reaction and result with regard to mainline events.