Explanation

Negative imperative in passive voice uses: "Let + object + not be + past participle."

"Don’t mistrust" becomes "Let ... not be mistrusted."

Hence, "Let the sincere not be mistrusted" is correct.

Explanation

Active voice: Has anybody done all the work?

Passive structure: Has + been + past participle

Subject ("anybody") becomes the agent, and object ("all the work") becomes the subject.

Passive: Has all the work been done by anybody?

Explanation

Active voice: "China has always tried to settle all issues with India."

Passive voice: "All issues with India have always been tried to settle by China."

The structure is:

has always tried → have always been tried

Object ("all issues with India") becomes the subject in passive voice.

Explanation

The sentence is in present tense (don’t suggest), so passive voice should also be in present tense → is not suggested.

The correct passive form:

Active: Why don’t you suggest him...?

Passive: Why is he not suggested by you...?

Explanation

Original sentence is in future simple tense (active voice):

Subject + will + base verb + object

→ The team will celebrate their victory.

Passive voice structure for future simple:

Object + will be + past participle + by + subject

→ The victory will be celebrated by the team tomorrow.

Explanation

The original sentence is in present simple active voice.

In passive voice:

Subject becomes object → The students' questions

Verb "answers" becomes are answered (present simple passive, plural subject)

Agent: by the teacher

Final sentence: The students' questions are always answered by the teacher.

Explanation

"Should keep" in active voice changes to "should be kept" in passive voice.

The object "one's promise" becomes the subject in passive form.

Explanation

When will a car be bought by you?

In passive voice, the structure is: "When + will + object + be + past participle + by subject."

"A car" (object) comes after "will", followed by "be bought" (passive form), and "by you" (subject).

Explanation

Will a song not have been sung by her?

In passive voice, the object ("a song") comes first, followed by the helping verbs ("will have been").

The past participle of "sing" is "sung", and the subject ("she") becomes "by her" at the end.

Explanation

The sentence "They have completed the project" is in the active voice, and the passive form is "The project has been completed by them".

This maintains the same tense (present perfect) while changing the subject and object.