The document provides information about the use of "used to", "be used to", and "get used to" in the past tense. It explains that "used to" is used with an infinitive verb to talk about habitual actions in the past. It notes that "be used to" takes a noun or verb-ing to talk about being accustomed to something. And it states that "get used to" also takes a noun or verb-ing, and means to become accustomed to something. Examples are provided for the use of each structure.