1. It isn’t necessary to book a table at the restaurant.
→ You don’t have to book a table at the restaurant.

2. Children are welcome to eat in the bar.
→ Children can eat in the bar.

3. Am I required to get a visa for Brazil? (have to)
→ Do I have to get a visa for Brazil?

4. It isn’t a good idea to do exercise after a big meal. (should)
→ You should not do exercise after a big meal.

5. My teachers let me leave school early yesterday afternoon. (allowed)
→ I was allowed to leave school early yesterday afternoon.

6. It’s OK to open the window. (can)
→ You can open the window.