The rarest verb form in English is widely considered to be the future perfect continuous in the passive voice. While often referred to as a "tense," it's more accurately described as a combination of tense (future), aspect (perfect continuous), and voice (passive).
Understanding Tense, Aspect, and Voice
To appreciate the rarity of this particular construction, it's helpful to differentiate between these grammatical elements:
- Tense: Indicates when an action occurs (past, present, future).
- Aspect: Describes the nature of the action in relation to time, such as whether it's completed, ongoing, or habitual. Common aspects include:
- Simple: (e.g., I walk)
- Continuous (or Progressive): An ongoing action (e.g., I am walking)
- Perfect: An action completed before another point in time (e.g., I have walked)
- Perfect Continuous: An action that began in the past and continues up to another point, often with emphasis on duration (e.g., I have been walking)
- Voice: Shows the relationship between the subject and the verb's action:
- Active Voice: The subject performs the action (e.g., The student writes the essay).
- Passive Voice: The subject receives the action (e.g., The essay is written by the student).
The Rarest English Verb Form: Future Perfect Continuous Passive
This highly complex structure describes an action that will have been ongoing for a period of time up to a specific point in the future, with the subject receiving the action.
Structure: Subject + will have been being + past participle (V3)
Example:
Consider the sentence: "By next Tuesday, the report will have been being reviewed by the committee for three hours."
Let's break down why this is so cumbersome and rarely used:
- Future: "will"
- Perfect: "have been"
- Continuous: "being" (indicating ongoing action)
- Passive: "reviewed" (the report is receiving the action of reviewing)
Why is it So Rare?
The extreme infrequency of the future perfect continuous in the passive voice stems from several factors:
- Complexity and Redundancy: The combination of "will have been being" creates a long, clunky, and often redundant construction. Simpler ways to express the same meaning almost always exist.
- Awkward Sound: Native speakers instinctively avoid such convoluted phrases because they sound unnatural and difficult to process.
- Lack of Practical Use: Situations requiring such a precise and layered meaning, specifically from a passive perspective, are rare. Usually, the active voice or a simpler passive construction is sufficient.
- Alternative Constructions: Most speakers would opt for clearer and more concise alternatives.
Practical Implications and Alternatives
In almost all cases, alternative grammatical structures can convey the same meaning more effectively.
Original (Rare): "By the time he arrives, the experiment will have been being conducted for an hour."
Possible Alternatives:
- Active Voice (Future Perfect Continuous): "By the time he arrives, they will have been conducting the experiment for an hour." (Much more common)
- Simpler Passive (Future Perfect Simple): "By the time he arrives, the experiment will have been conducted for an hour." (If the continuous aspect isn't crucial)
- Rephrasing for Clarity: "By the time he arrives, the experiment will have been underway for an hour."
- Changing the Subject: "By the time he arrives, the scientists will have been working on the experiment for an hour."
The existence of numerous clearer and less cumbersome ways to express similar ideas makes the future perfect continuous in the passive voice an almost hypothetical grammatical structure, rarely encountered in natural English communication.
