In texts and very casual emails, people write 2 for to or too, because those words sound like the number two. You might see “going 2 school” or “me 2”. It is a shortcut, not a new word, and it does not tell you which spelling they meant — you have to read the rest of the line. Though actually, many people mix this with other number tricks in the same message, which is why it looks messy to anyone who is not in the chat. Never use it in school work, job mail, or anything a teacher will mark.

聊天、簡訊裡用 2 來寫 to 或 too（諧音 two）。作文、考試不要用。