お〜・ご〜
Honorific prefixes for nouns and adjectivesmachine translation
Formationお + native Japanese words (お名前・お仕事); ご + Sino-Japanese words (ご家族・ご住所)
The prefixes お・ご attach to nouns and adjectives to show respect for the person connected to that thing: お名前 (your name), ご家族 (your family). The rule for choosing: お goes with native Japanese words (お名前、お仕事、お店), ご goes with Sino-Japanese words — compounds read with the Chinese-style readings of the kanji (ご家族、ご住所、ご質問、ご旅行). A few well-worn exceptions take お despite being Sino-Japanese: お電話、お食事、お料理、お時間、お元気.
The usage principle: put お・ご before things that BELONG TO THE OTHER PERSON, not before your own — ask お名前は？ but when introducing yourself, just say 名前 (except in the humble frame お〜する, covered in a later lesson). Loanwords written in katakana don't take these prefixes: there is no ×おビール.
Separately, one group of words has お・ご permanently attached as fixed refined words, used even for your own things: お茶、お金、お水、お土産、ご飯 — drop the prefix and the sentence sounds noticeably blunt. You've seen them since N5; now you know why they always carry お・ご. This prefix is also a building block of three important honorific patterns coming up: お〜になる、お〜ください、お〜する.
Examples
お名前を教えてください。
Please tell me your name.
ご家族は何人ですか。
How many people are in your family?
先生はお元気ですか。
Are you doing well, sensei?