Unit 3: Grammar : I- The past perfect Definition: The past perfect is a verb tense which is used to show that an action took place once or many times before another point in the past. Read on for detailed descriptions, examples, and present perfect exercises. Past Perfect Forms: The past perfect is formed using had + past participle . Questions are indicated by inverting the subject and had . Negatives are made with not . Statement: You had studied English before you moved to ...