The document discusses the future in the past tense in English grammar. It explains that the future in the past is used to talk about plans or intentions in the past that may or may not have happened. It presents the structures for forming the future in the past, which include "was/were going to" followed by the base form of the verb. It also discusses using "would" to form the future in the past after statements including verbs like "think", "hope", and "expect". Examples are provided to illustrate the use of the future in the past tense.