Understanding Active and Passive Voice Transformation

The question asks us to convert a sentence from active voice to passive voice. Active voice emphasizes the doer of the action, while passive voice emphasizes the action itself or the receiver of the action. The original sentence provided is: "The chief scientist is believed to have been coordinating cross-lab efforts since the early stages of the project."

Analyzing the Original Sentence

Let's break down the original sentence:

• Main Clause Verb: "is believed" (This part is already in the passive voice).
• Infinitive Phrase: "to have been coordinating cross-lab efforts since the early stages of the project." This phrase describes the action related to the belief.
• Subject of the Infinitive Action: "The chief scientist" (This is the one performing the coordinating).
• Object of the Infinitive Action: "cross-lab efforts" (This is what is being coordinated).
• Tense of the Infinitive Action: "to have been coordinating" indicates a past continuous action relative to the belief.

The task is essentially to restructure the sentence so that "cross-lab efforts" becomes the primary subject, and the belief is stated about it, reflecting the original tense and action.

Step-by-Step Passive Voice Conversion

To convert this sentence to passive voice effectively, where "cross-lab efforts" becomes the subject, we follow these steps:

1. Identify the Object: The object of the action "coordinating" is "cross-lab efforts". This will become the subject of the new passive sentence.
2. Maintain the Main Passive Verb: The main verb "is believed" is already passive. When "cross-lab efforts" becomes the subject, this verb changes to "are believed" to agree with the new plural subject.
3. Transform the Infinitive Phrase: The original infinitive phrase "to have been coordinating" describes a past continuous action. The passive transformation requires reflecting this action. The structure "to have been + past participle" is used to form the passive infinitive corresponding to a past perfect continuous action.
4. Incorporate the Agent: The original subject ("The chief scientist") becomes the agent in the passive sentence, introduced by the preposition "by".

Evaluating the Options

Let's examine each option:

• Option 1: "Cross-lab efforts are believed to being have coordinated..." - This contains a grammatical error ("to being").
• Option 2: "Cross-lab efforts are being coordinated..." - This changes the main verb tense from "are believed" to "are being coordinated", losing the element of belief.
• Option 3: "Cross-lab efforts are believed to have been being coordinated..." - While attempting to reflect the continuous nature, the structure "to have been being coordinated" is grammatically awkward and rarely used.
• Option 4: "Cross-lab efforts are believed to have been coordinated by the chief scientist since the early stages of the project." - This option correctly identifies "cross-lab efforts" as the subject, uses the appropriate passive verb "are believed", and employs the standard passive infinitive form "to have been coordinated". This structure correctly conveys the belief about the action performed by the chief scientist.

Conclusion on Correct Transformation

The transformation requires making the object of the original action ("cross-lab efforts") the subject of the sentence. The main verb "is believed" adjusts to "are believed" for subject-verb agreement. The phrase "to have been coordinating" needs to be converted into its passive infinitive form. The structure "to have been + past participle" is the standard way to express a passive belief about a past perfect continuous action in this context. Option 4 correctly applies this structure.