The key answer of exercise 2

Past Perfect Simple (had + past participle)

• "Jay had chosen a skater style."
• "None of the students had heard of normcore style."

These instances of past perfect simple are used to describe actions that occurred before a specific point in the past. In the context, they describe actions that happened before Jay's participation in the workshop and before the students' introduction to normcore style.

Past Simple

• "He started a new school there and decided to join a school workshop."
• "The workshop had already started."
• "When she arrived, the workshop had already started."

These instances of past simple describe actions that occurred at specific points in the past. They narrate events that happened sequentially in the story, such as Jay starting a new school, the beginning of the workshop, and Eve's arrival at the workshop.

The past perfect simple is used to indicate actions that were completed before a specific point in the past (usually indicated by another past action), while the past simple is used to describe actions that happened at specific points in the past.