Change the following sentences as directed:

The person who teaches us ought to be obeyed.

This sentence has been transformed from active voice to passive voice. In the original active sentence, "We" is the subject performing the action of obeying. In the passive voice, the object of the active sentence ("the person who teaches us") becomes the subject, and the focus shifts to the action being received.

The transformation follows these steps:

    
• Identify the object of the active sentence: "the person who teaches us". This becomes the subject of the passive sentence.
    
• Identify the modal auxiliary verb: "ought to".
    
• Apply the passive structure for modals: For sentences with modal verbs, the structure is Modal + be + Past Participle (V3). So, "ought to obey" becomes "ought to be obeyed".
    
• The original subject as agent: The original subject "We" can be introduced with "by" (e.g., "by us"). However, when the agent (doer of the action) is general or not particularly important (like "we," "they," "people"), it is often omitted for conciseness and natural flow, especially when the emphasis is on the action or the receiver of the action.

Therefore, the passive voice construction is "The person who teaches us ought to be obeyed."

This sentence transformation involves changing an affirmative sentence into a negative one while preserving its original meaning. The original sentence, "Everyone dislikes dishonest persons," indicates that all individuals have a negative sentiment towards dishonest people.

To achieve the negative transformation without altering the meaning, the universal affirmative subject "Everyone" is replaced by the universal negative subject "No one." Consequently, the verb "dislikes" must be changed to its antonym "likes" to maintain semantic equivalence. This ensures that the transformed sentence "No one likes dishonest persons" conveys the identical message as the original.

Such transformations are common in competitive examinations for job seekers, testing their understanding of grammatical rules, vocabulary (especially antonyms), and the ability to manipulate sentence structure while maintaining clarity and original intent.

Because he was ill, he didn't take the test.

A complex sentence is characterized by having one independent clause and at least one dependent (or subordinate) clause. The original sentence, "Due to his illness, he didn't take the test," is a simple sentence where the cause is expressed through a prepositional phrase ("Due to his illness").

To convert it into a complex sentence, we replace the prepositional phrase with a subordinate clause that explains the reason. By using a subordinating conjunction like 'because' or 'as', we create a dependent clause that modifies the main clause. In the example, "Because he was ill" is the dependent adverbial clause of reason, and "he didn't take the test" is the independent clause, thus forming a complex sentence.

He said that he was preparing for the exam.

When converting direct speech to indirect speech, several changes occur, especially when the reporting verb is in the past tense, as in "He said".

    
• Change in Tense: If the reporting verb is in the past tense, the tense of the verb in the reported speech usually shifts to a corresponding past tense. In this case, "I am preparing" (Present Continuous) changes to "he was preparing" (Past Continuous).
    
• Change in Pronoun: The pronoun 'I' refers to the speaker (He), so it changes to 'he' in indirect speech to maintain consistency.
    
• Conjunction: The conjunction 'that' is commonly used to introduce the reported speech, although it can sometimes be omitted without changing the meaning.
    
• Removal of Quotation Marks: The quotation marks are removed, and the comma after the reporting verb is replaced by the conjunction 'that'.

A tag question is a short question added to the end of a statement. Its purpose is often to confirm information or to invite agreement.

To form a tag question for the sentence "Nobody believes a liar," consider the following rules:

    
• Negative Statement, Positive Tag: The statement "Nobody believes a liar" is negative due to the word "Nobody." Therefore, the tag question must be positive.
    
• Subject Pronoun for "Nobody": When the subject of the main clause is an indefinite pronoun like "nobody," "somebody," "everybody," "no one," or "everyone," the pronoun used in the tag question is "they."
    
• Auxiliary Verb: The main verb "believes" is in the simple present tense. For a positive tag with "they" in the simple present, the auxiliary verb used is "do."

Combining these rules, the correct tag question is "do they?"