Select the option that expresses the given sentence in passive voice.

The sewage water smells foul.

The correct answer is "The sewage water is foul when it is smelt".

Key Points

• In active voice, sometimes verbs can certainly be followed by adjectives. This typically happens with linking verbs.
• Linking verbs do not express action. Instead, they connect the subject of the verb to additional information about that subject.
• The most common linking verb is "to be," but others include "seem," "become," "appear," etc.
• Here are a few examples:
  • The cake is delicious.
  • He seems tired.
  • She became furious.
  • The weather appears gloomy.
• For example: Active: Rose smells sweet. 
  • Passive: Rose is sweet when it is smelt. 
• Passive Structure: Subject + Verb (A/c tense & number) + Adjective + when + pronoun (A/c number) + H.V + 3rd form of verb (M.V in 3rd form) 
  • Active: Those mangoes tasted sour. 
  • Passive: Those mangoes were sour when they were tasted. 
• From the above explanation it is clear that the correct sentence is: "The sewage water is foul when it is smelt".

Therefore, the correct answer is "Option 4".

Note: The official answer key marks "Passive construction is not possible" as the correct answer. 

Additional Information

• These passive voice examples might seem a little odd and that's because not all sentences, especially those with linking verbs and adjectives, translate naturally to the passive voice.
• The passive voice is typically formed by phrases that look like "is/are/was/were + past participle," but when adjectives are involved, especially with linking verbs like be/seem/become/appear, the formulation of passive voice can be less straightforward and less commonly used.
• Usually, passive voice is more commonly used when an action verb is involved:
  • For example: Active: The cat chased the mouse.
    • Passive: The mouse was chased by the cat.