THE USAGE OF 'MUST HAVE' IN DIFFERENT SENTENCES STRUCTURES

THE USAGE OF 'MUST HAVE' IN DIFFERENT SENTENCES STRUCTURES

The phrase must have been in the passive voice is used to express a strong assumption or conclusion about an action that was likely performed on the subject in the past. It indicates a high level of certainty that something was done to the subject, based on evidence or logical reasoning. This construction is followed by the past participle (V3) of the verb and is used in different sentence forms, including affirmative statements, questions, and negative questions, to convey a confident deduction about what happened to the subject.

🎯 Must have

Affirmative
O + must + have + been + V3 + [by + S]
This decision must have been made by the committee.

Verbal Question
Must + O + have + been + V3 + [by + S] + ? 
Must this decision have been made by the committee?

Negative Verbal Question
Mustn't + O + have + been + V3 + [by + S] + ?
Mustn't this decision have been made by the committee?

'Wh' Question
Wh + must + O + have + been + V3 + [by + S] + ?
Why must this decision have been made by the committee?

Negative 'Wh' Question
Wh + mustn't + O + have + been + V3 + [by + S] + ?
Why mustn't this decision have been made by the committee?