The document discusses frequency adverbs and expressions used to describe how often something happens. It notes that frequency adverbs are placed before the main verb in the present simple tense but after the verb "to be." It provides examples of questions using frequency expressions like "how often" and placement of adverbs and expressions like "once a week," "every day," and "twice a month." The document also includes exercises placing frequency adverbs in sentences correctly and answering questions using adverbs and expressions.