1. The document discusses the use of adverb clauses to show time relations in sentences, including the tenses used in the main and subordinate clauses for different time frames like past, present, and future.
2. Examples are provided to illustrate the tenses used in main and subordinate clauses with time-related adverb clauses introduced by words like after, when, while, as soon as, until, and whenever.
3. Special constructions like by the time, since, the first time, the last time, and the next time are also examined for the tenses used in the related clauses.