4. Read the sentences. Which shows that something is/isn't necessary?

Sentence Analysis:

• You have to pay the rent on time. - This sentence expresses an obligation or necessity.
• You don't have to/needn't bring your own bedsheets. - This sentence expresses that something is not necessary.
• You need to pack your things properly. - This sentence expresses a necessity.

Answer: The sentence "You don't have to/needn't bring your own bedsheets." shows that something isn't necessary.