The document discusses the differences between "used to" and "be used to". Used to is used to talk about past habitual activities that are no longer happening, while be used to refers to past activities that are still ongoing in the present. It provides examples of sentence structures and sample sentences for both phrases, such as "She used to sleep late when she was young" and "She is used to study English for two hours". The document also lists common verbs that can be used with used to and be used to to talk about habitual past activities.