The active voice sentence is "The theatre was keeping a seat for you." Choose the option that best expresses this sentence in the passive voice.

Introduction / Context:
This question examines the learner's ability to convert a past continuous tense sentence in the active voice into its passive voice equivalent. The original sentence focuses on the theatre performing the ongoing action of keeping a seat for someone. In the passive version, the focus moves to the seat that is being kept, while the tense remains past continuous.

Given Data / Assumptions:

• Active sentence: The theatre was keeping a seat for you.
• Subject: the theatre.
• Object: a seat.
• Indirect object: for you.
• Verb phrase: was keeping (past continuous).

Concept / Approach:
The passive form of the past continuous tense uses the structure: subject (former object) + was/were + being + past participle. Here, the object "a seat" becomes the subject of the passive version. The verb "was keeping" changes to "was being kept," and we retain "for you" as part of the sentence. We also keep the agent phrase "by the theatre" to show who was performing the action, although in natural language the agent is sometimes omitted.

Step-by-Step Solution:

Step 1: Identify the object "a seat," which will become the subject in the passive sentence. Step 2: Recognise that "was keeping" is past continuous; the passive form must therefore be "was being kept." Step 3: Retain the phrase "for you," since it shows the beneficiary of the action. Step 4: Add the agent phrase "by the theatre" to show who was keeping the seat. The complete passive sentence becomes: "A seat was being kept for you by the theatre."

Verification / Alternative check:
The sentence "A seat was being kept for you by the theatre" maintains the original meaning and correctly reflects past continuous passive. The subject is now "a seat," the form "was being kept" mirrors "was keeping," and the phrases "for you" and "by the theatre" preserve beneficiary and agent. It reads naturally and is grammatically sound.

Why Other Options Are Wrong:

Option B: "Keeping of a seat for you has been done by the theatre." changes the tense to present perfect passive ("has been done") and uses an unnatural nominalisation "keeping of a seat." Option C: "The theatre has kept a seat for you." is present perfect active, not passive, and shifts the focus back to the theatre. Option D: "A seat would be kept for you by the theatre." uses "would be kept," which expresses a different time and condition, not a past continuous action. Option E: "You were having a seat kept for you by the theatre." has a different structure and slightly different meaning; it does not follow the standard transformation of the given sentence.

Common Pitfalls:
Students sometimes omit "being" in past continuous passive forms, creating incorrect structures like "was kept" instead of "was being kept." Another error is changing the tense, for example switching to present perfect or simple past, which no longer accurately reflects the original progressive action. Always match the tense and aspect of the original sentence when performing voice transformations.

Final Answer:
The correct passive voice sentence is A seat was being kept for you by the theatre.