Improve the bracketed part of the sentence by choosing the best alternative: He (promised to mend) his ways.

Introduction / Context:
Sentence improvement questions sometimes test your ability to recognise when a sentence is already correct. This is just as important as spotting errors. In the sentence "He promised to mend his ways", the phrase "promised to mend" is a standard, grammatically correct construction that needs no change. The distractor options introduce errors in tense, preposition, or structure.

Given Data / Assumptions:

• Original sentence: "He (promised to mend) his ways."
• The bracketed part may or may not need improvement.
• Options include three rephrasings and "No improvement".
• The intended meaning is simply that he gave a promise to improve his behaviour.

Concept / Approach:
The verb "promise" is correctly followed by "to" plus the base form of another verb to indicate what someone promises to do, for example, "promised to help", "promised to pay", "promised to mend". The noun phrase "his ways" refers to his behaviour or habits. The entire phrase "promised to mend his ways" is a well-formed idiomatic expression in English. We must check if any alternative makes the sentence clearer or more correct. If not, "No improvement" is the right choice.

Step-by-Step Solution:
Step 1: Evaluate the given phrase "promised to mend". It follows the correct verb + to-infinitive pattern.Step 2: Consider option A: "had a promised to mending". This is ungrammatical: "had a promised" is wrong and "to mending" is also incorrect after "to".Step 3: Consider option B: "promised for mending". The preposition "for" is wrong here; we do not say "promise for doing" in this sense.Step 4: Consider option C: "was promised of mending". This changes the voice and meaning; it suggests someone else promised him something, and "of mending" is not idiomatic.Step 5: Option D, "No improvement", keeps the natural and correct original phrase.Step 6: Therefore, the best answer is "No improvement".

Verification / Alternative check:
We can verify by comparing with other standard examples: "He promised to work harder", "She promised to arrive early", "They promised to pay the bill on time". In each case, "to + verb" follows "promised" directly. If we replace "to" with "for" or switch to "to mending", the sentences become unnatural or wrong. The structure in the original sentence fits this clear pattern, confirming that no change is required.

Why Other Options Are Wrong:
Option A ("had a promised to mending") is incorrect in both verb form and structure; it does not conform to any standard English pattern. Option B ("promised for mending") misuses "for" and disrupts the natural verb pattern. Option C ("was promised of mending") changes the meaning completely and also uses the wrong preposition. Only the original phrase accurately and clearly expresses the idea that he himself promised to improve his behaviour.

Common Pitfalls:
Candidates often assume that every bracketed phrase must be wrong and mechanically choose a rewritten option. This habit leads to unnecessary changes in already correct sentences. The key is to evaluate the given phrase first; if it is both grammatically correct and idiomatic, then "No improvement" is often the best answer. Train yourself to compare all options rather than immediately rejecting the original.

Final Answer:
The sentence is already correct, so the right choice is "No improvement".