hi

Hi is a common informal interjection used as a greeting in English. It is typically spoken to acknowledge someone’s presence or to begin a conversation. In written language, hi appears most often in casual communication such as text messages, emails among friends, or social media, and it is frequently punctuated with an exclamation mark or a question mark to convey tone.

Pronunciation of hi is generally /haɪ/ in English, and it is understood by speakers across many dialects. The term is regarded as informal; in formal settings, speakers may choose alternatives such as hello, good morning, or good afternoon to convey a more measured tone. The use of hi can convey friendliness or casual familiarity, and its appropriateness depends on context, relationship, and cultural norms of address.

Etymology and history: the exact origin of hi as a greeting is uncertain. It likely developed as a clipped form of earlier exclamations such as hey or hie and became common in English-speaking communities during the 19th and 20th centuries. Over time, its spelling and usage stabilized as the short, simple greeting known today.

Other uses and disambiguation: in uppercase form, HI can denote things beyond the greeting, such as the chemical formula for hydrogen iodide, or serve as the postal abbreviation for the U.S. state of Hawaii. In various domains, HI can appear as an acronym or initialism for different organizations, terms, or products, but those uses are distinct from the greeting sense of hi.