There are a few set phrases and words that come with “o” and “go” built right in. Things like “onegai”, “okyakusan”, “onamae ha nan desu ka” and so on. You can find these in just about any beginning level textbook or tourist guidebook and memorizing them would be a good way to spend an evening or two if you ever decide to actually go to Japan.
Outside of these set phrases it can be hard to figuring out when you should and shouldn’t add “o” or “go” to words. It’s something you just have to develop an instinct for by listening to lots of real Japanese. But don’t worry too much; as long as you remember to use polite verbs I imagine most Japanese will think you’re doing pretty good for a foreigner.
御 = お or ご = Honorific word prefix
Blue: Remember how you can make verbs more polite by conjugating them?
Yellow: That’s what we use ます for.
Blue: Well, you can also make some non-verbs more polite by adding an お or ご to the front of the word.
Blue: There’s a kanji form too: 御.
Blue: So when you ask someone what their name is it’s polite to use お名前.
Blue: But remember, it’s rude to use honorifics when talking about yourself. Use plain 名前 for your own introductions.
Yellow: I need a T-shirt that says: “I’m not rude, honorifics are confusing”.