1. The document discusses the future perfect tense and past future perfect tense.
2. The future perfect tense is used to refer to an action that will be completed by a certain time in the future. It uses the forms "will have done" and "be going to have done."
3. The past future perfect tense refers to a past time that would be future relative to another past time point. It uses the forms "would have done" and "should have done."