**Rule**: For an interrogative sentence in the Future Perfect Tense starting with 'Who', the passive structure is **By whom + will/shall + have been + V3?** - **Correct Answer (b)**: 'Who' changes to 'By whom'. The Future Perfect passive verb 'will have been finished' is used correctly with the object 'the work'. - **Incorrect Answer (a)**: This incorrectly uses the Future Simple passive form ('will be finished'). - **Incorrect Answer (c)**: 'would' is an incorrect modal change. - **Incorrect Answer (d)**: This word order is not standard for formal interrogative sentences.

**Rule**: When the active sentence uses 'has to' to show necessity, the passive form is **Object + has/have to + be + V3**. - **Correct Answer (d)**: The object 'a new manager' becomes the subject. Since 'manager' is singular, it takes 'has to be', followed by the past participle 'hired'. - **Incorrect Answer (a)**: 'has been hired' is the passive of the Present Perfect Tense. - **Incorrect Answer (b)**: 'is to be' implies a plan, not the necessity of 'has to'. - **Incorrect Answer (c)**: 'had to be' incorrectly changes the tense to the past.

**Rule**: For active sentences using the 'be going to' future form, the passive structure is **Object + is/am/are + going to be + V3**. - **Correct Answer (c)**: The object 'a new library' becomes the subject. The structure 'is going to be built' is the correct passive conversion. - **Incorrect Answer (a)**: This incorrectly changes the tense to Simple Present. - **Incorrect Answer (b)**: This changes the structure to the 'will' future, which is not a direct conversion. - **Incorrect Answer (d)**: This is the passive of the Present Continuous tense ('is building'), not the 'going to' future.

**Rule**: For a sentence in the Present Perfect Tense, the passive voice structure is **Object + has/have + been + V3 + by + Subject**. - **Correct Answer (d)**: The object 'a delicious meal' becomes the subject. Since it is singular, 'has' is used, followed by 'been' and the past participle 'cooked'. - **Incorrect Answer (a)**: This incorrectly changes the tense to Simple Past. - **Incorrect Answer (b)**: This incorrectly changes the tense to Simple Present. - **Incorrect Answer (c)**: This incorrectly changes the tense to Past Perfect.

**Rule**: For an interrogative sentence with the 'be going to' future form, the passive structure is **Wh- word + is/am/are + object + going to be + V3?** - **Correct Answer (a)**: 'When' remains at the beginning. The object 'the work' is singular, so 'is' is used, followed by the object and the correct passive structure 'going to be finished'. - **Incorrect Answer (b)**: This changes the structure to the 'will' future. - **Incorrect Answer (c)**: This incorrectly changes the tense to the past. - **Incorrect Answer (d)**: The verb 'are' is incorrect because the subject 'work' is singular (uncountable).

**Rule**: When the active sentence uses 'had to' with a phrasal verb, the passive form is **Object + had to + be + V3 + particle**. - **Correct Answer (c)**: The object 'several employees' becomes the subject. The structure 'had to be laid off' is the correct passive form for the past necessity, keeping the particle 'off' with the verb. - **Incorrect Answer (a)**: 'had been laid off' is the passive of the Past Perfect Tense. - **Incorrect Answer (b)**: 'have to be' incorrectly changes the tense to the present. - **Incorrect Answer (d)**: 'were to be' implies a past plan, which is a different meaning.

**Rule**: Imperative sentences starting with 'Let us' can indicate a proposal or a simple command. This ambiguity allows for multiple passive forms. - **Correct Answer (d)**: Both (b) and (c) are valid passive interpretations. - (b) **'Let the game be finished'** treats the sentence as a direct imperative and uses the standard 'Let' structure. - (c) **'It is proposed that we should finish the game'** interprets 'Let us' as a proposal or suggestion. - **Incorrect Answer (a)**: 'should be finished' is a statement of advice, which is a possible but less direct conversion. - **Incorrect Answer (b)**: This is correct, but (c) is also a valid interpretation. - **Incorrect Answer (c)**: This is correct, but (b) is also a valid interpretation.

**Rule**: For interrogative sentences in the Future Simple Tense starting with a 'Wh-' word, the passive structure is **Wh- word + will/shall + object + not + be + V3 + by + subject?** - **Correct Answer (d)**: The 'Wh-' word 'Why' remains at the beginning. The modal 'will' comes next, followed by the new subject 'you', 'not be', and the past participle 'helped'. - **Incorrect Answer (a)**: While 'won't' is a contraction of 'will not', the structure in (d) is more formal and a clearer transformation. - **Incorrect Answer (b)**: The word order is incorrect for a question; 'will' should come before 'you'. - **Incorrect Answer (c)**: 'would' is an incorrect modal change.

**Rule**: For an interrogative sentence with the 'be going to' future form starting with 'Who', the passive structure is **By whom + is/am/are + object + going to be + V3?** - **Correct Answer (a)**: 'Who' changes to 'By whom'. The object 'the presentation' is singular, so 'is' is used, followed by the object and the correct passive structure 'going to be given'. - **Incorrect Answer (b)**: This changes the structure to the 'will' future. - **Incorrect Answer (c)**: 'who' is the incorrect case; 'whom' is required after the preposition 'By'. - **Incorrect Answer (d)**: This word order is not standard for formal interrogative sentences.

**Rule**: When the active sentence uses 'was to'/'were to' to indicate a past plan or arrangement, the passive form is **Object + was/were to + be + V3**. - **Correct Answer (c)**: The object 'the assignment' becomes the subject. The structure 'was to be submitted' is the correct passive form corresponding to the active 'was to submit'. - **Incorrect Answer (a)**: 'was being submitted' is the passive of the Past Continuous Tense. - **Incorrect Answer (b)**: 'had to be' implies past necessity, which is a different meaning. - **Incorrect Answer (d)**: 'was to have been' implies an unfulfilled past plan, which slightly changes the meaning.