Present Simple Passive:
Subject + am/ are /is + past participle (+ optional agent introduced by "by").
Past Simple Passive:
Subject + was / were + past participle (+ optional agent introduced by "by").
Examples:
Active: The chef cooks the meal.
Passive: The meal is cooked (by the chef).
Active: She wrote a book.
Passive: A book was written (by her).
Active: They will complete the project next week.
Passive: The project will be completed next week.