To achieve effective dialogue processing, the kinds of daily conversations people have must be clarified. Unfortunately, the characteristics of everyday conversations remain insufficiently investigated. In recent years, the Corpus of Everyday Japanese Conversation (CEJC) was developed, which is a large-scale corpus constructed by recording everyday Japanese conversations. In this article, we investigate the linguistic variations of everyday conversations in a multitude of situations using CEJC. We conducted factor analysis of it using the semantic categories of functional expressions that represent such subjective information as modality, thoughts, and communicative intention in addition to various tenses and facts. Our analysis identified seven factors that characterize everyday conversations and suggests that they are expressed by a combination of a dialogue’s purpose (e.g., “Explanation” and “Suggestion”) and its manners (e.g., “Politeness” and “Involvement”). We also analyzed the BTSJ–Japanese natural conversation corpus with transcripts and recordings and the Nagoya University conversational corpus and confirmed the generalizability of these factors.