This sentence has been deleted from the course database, but it has yet to vanish from the system. It may have appeared before ti/chi had been explained.

• ti is used only when speaking to just one person, and that person is someone whom you know well and with whom you are an familiar terms - family and good friends, children, etc.

• chi is used for speaking to two or more people, or to any individuals with whom you are not on familiar terms.

Rather similar to the French tu, vous and the German du, Sie