Sentence Improvement
~13 min read
- What: Sentence Improvement gives a sentence with an underlined part and three possible substitutions. Pick the substitution that improves the sentence — or (d) "No improvement" if the original is correct.
- Why it matters: The block carries 5–10 items in papers where NDA uses it (especially 2015–2017). The skills overlap heavily with Spotting Errors — prep one, you have largely prepped the other.
- Key habit: Three of the four options are usually grammatically possible. The right one fixes the specific error and introduces no new problem. Always check the candidate substitution against the rest of the sentence.
Sentence Improvement is the cousin of Spotting Errors. Both blocks test the same grammar errors; only the form changes — Spotting Errors asks "where is the error?", Sentence Improvement asks "which fix is the best?". From 2018 onwards, NDA has often replaced the standalone Sentence Improvement block with extended Spotting Errors, but the topic remains active in many state and central exams and in earlier NDA papers.
The biggest mental shift from Spotting Errors is the (d) option. There it is "No error". Here it is "No improvement" — meaning the underlined part is already correct as it stands, and none of the substitutions is better. Like its sibling, the (d) option is correct roughly 15–20% of the time.
This page lays out the method, the eight substitution patterns NDA tests most, and worked PYQ examples. Pair it with Spotting Errors for grammar overlap and Identifying Correct Sentences for the four-option grammar-judgment skill.
What Sentence Improvement Tests
NDA Sentence Improvement — Question Format
- Item type: One sentence with an underlined part. Three possible substitutions labelled (a), (b), (c). Option (d) = "No improvement" — the underlined part as it stands is best.
- Instruction: "If one of (a), (b) or (c) is better than the underlined part, indicate your response on the Answer Sheet against that letter. If none improves the sentence, indicate (d)."
- Number: Usually 10 items in NDA papers from 2015 to 2017; sometimes embedded inside other blocks in later papers.
- Difficulty: Mixed. About half the items have one clear improvement; the rest are subtle — two options arguably "improve" the sentence but only one is the cleanest fix.
Exam Pattern & Weightage
| Year / Paper | No. of Items | Pattern Notes |
|---|---|---|
| 2015-I | 10 | Standard 4-option format |
| 2015-II | 10 | Standard pattern |
| 2016-I | 10 | Standard pattern |
| 2016-II | 10 | Standard pattern |
| 2017-I | 10 | Final paper with a dedicated full block |
| 2018 onwards | Embedded | Reduced or merged with Spotting Errors / Identifying Correct Sentences |
Even if Sentence Improvement does not appear as a standalone block, the grammar patterns it tests show up inside Spotting Errors and Identifying Correct Sentences. Prepare these three topics as a group; the marginal cost is small and the marks compound.
The Three-Option Method
Sentence Improvement rewards a disciplined comparison rather than instinct. Use these three steps:
- Read the full sentence (not just the underlined part). Many improvements hinge on tense/number/article agreement with words outside the underlined part. A substitution that fixes one thing but breaks another is wrong.
- Diagnose the error in the underlined part. Run a fast 5-pass scan (S-V, tense, preposition, article, idiom). If you cannot name the error, the answer may well be (d) No improvement.
- Test each substitution by plugging it back in. Read the full sentence with the substitution. If it now reads cleanly with no new error, that is your answer.
The "Better" Test
- An option is "better" only if it fixes a real error and introduces no new error.
- If two options are both grammatically clean, pick the simpler one — NDA prefers economy over elaboration.
- If no option reads cleaner than the original, (d) No improvement is your answer.
The "No Improvement" Decision Rule
Underconfident candidates rarely pick (d). Overconfident candidates pick (d) when there is in fact an improvement. Use this rule:
Pick (d) only when all three of these hold:
- You cannot name a grammatical error in the underlined part using the 5-pass scan.
- Each of (a), (b), (c) either repeats the same construction with a stylistic shuffle, or introduces a new error.
- Plugging the underlined part back in reads fluently with no jarring spot.
Average frequency in NDA: ~1 in 5–6 items has (d) as the correct answer. Don't avoid (d), but don't reach for it either.
Eight Substitution Patterns NDA Tests
Pattern 1 — Tense Fix
Stem (NDA 2015-II): "Until you don't finish the work, you won't be given leave." (Until already negates; "don't" is double negative.)
Substitution: "Until you finish".
Rule: "Until" already means "up to the time when not"; don't add another negative.
Pattern 2 — Conditional Fix
Stem (NDA 2015-II): "Had she been hungry, she would have devoured the whole lot of it."
Substitution options: "Unless she had been hungry" / "However she had been hungry" / "As if she had been hungry" / No improvement.
Rule: The "Had + S + past participle" inversion = Type 3 conditional. None of the substitutions match that structure. Answer: (d) No improvement.
Pattern 3 — Preposition Fix
Stem: "He is married with her since 2010."
Substitution: "married to her since 2010" or "has been married to her since 2010".
Rule: Marry takes to, not with. Since needs perfect tenses.
Pattern 4 — Subject-Verb Agreement Fix
Stem: "Each of the boys have received a prize."
Substitution: "Each of the boys has received".
Rule: "Each" → singular verb, regardless of intervening plural noun.
Pattern 5 — Modal / Auxiliary Fix
Stem: "You need not to worry about the result."
Substitution: "need not worry" (the modal "need" takes the base form directly; no "to").
Rule: Modal verbs (can, may, must, should, need as modal) take base form, not infinitive with "to".
Pattern 6 — Article Fix
Stem: "An unique opportunity arose."
Substitution: "A unique" (uniquesounds like "you-neek" — consonant sound).
Rule: Article depends on the sound of the next word, not its first letter.
Pattern 7 — Idiomatic Construction Fix
Stem: "Hardly had I reached the station than the train left."
Substitution: "Hardly had I reached the station when the train left."
Rule: Hardly ... when (not than). No sooner ... than. Don't mix the pairs.
Pattern 8 — Redundancy / Wordiness Fix
Stem: "We returned back from Delhi yesterday."
Substitution: "returned from Delhi" or "came back from Delhi".
Rule: "Return" already implies "back"; don't double it.
Worked Examples from NDA PYQs
Worked Example 1 — Type 3 Conditional (NDA 2015-II, Q1)
Stem: "Had she been hungry, she would have devoured the whole lot of it."
Options: (a) Unless she had been hungry (b) However she had been hungry (c) As if she had been hungry (d) No improvement
Diagnosis: The underlined "Had she been hungry" is a Type 3 conditional inversion — fully correct.
Test substitutions: "Unless she had been hungry" inverts meaning; "However" doesn't fit; "As if" changes the sense.
Answer: (d) No improvement.
Lesson: Inverted conditionals (Had S V, S would V) sound unusual but are entirely correct.
Worked Example 2 — Until + Negative (NDA 2015-II, Q2)
Stem: "Until you don't finish the work, you won't be given leave."
Options: (a) Until you must finish (b) Until finishing (c) Until you finish (d) No improvement
Diagnosis: "Until" + "don't" = double negative. "Until you finish" already means "up to the point when you have not finished".
Test substitutions: (a) is awkward; (b) is non-standard; (c) is clean.
Answer: (c) Until you finish.
Lesson: Unless and Until both contain a hidden "not". Never add another negative.
Worked Example 3 — Article (NDA 2015–17 typical)
Stem: "It is an universal truth."
Options: (a) the universal (b) a universal (c) one universal (d) No improvement
Diagnosis: "Universal" starts with the consonant sound "yoo-" — takes "a", not "an".
Test: (a) "the universal" works but means a specific universal truth — slight meaning shift. (b) "a universal" fixes the article cleanly.
Answer: (b) a universal.
Memory: An honest man / an MP (vowel sounds), a university / a one-eyed beggar (consonant sounds).
Worked Example 4 — Tense Sequence
Stem: "He told me that he has been ill since Monday."
Options: (a) had been ill (b) is ill (c) was ill (d) No improvement
Diagnosis: Reporting verb "told" is in past tense. Reported-speech rule shifts present perfect → past perfect.
Answer: (a) had been ill.
Lesson: When the reporting verb is past, shift the reported verb one tense back.
Worked Example 5 — Modal Auxiliary
Stem: "She can able to swim across the river."
Options: (a) is able to (b) can (c) was able to (d) No improvement
Diagnosis: "Can" and "be able to" are both used for ability — never both together.
Test: (a) and (b) are both grammatical fixes. Pick the simpler / closer to the original. (b) "can" alone fixes the redundancy without changing tense.
Answer: (b) can.
Worked Example 6 — Preposition Fix
Stem: "I have been waiting since two hours."
Options: (a) from (b) for (c) at (d) No improvement
Diagnosis: Since takes a point in time (since Monday, since 2010); for takes a duration (for two hours).
Answer: (b) for.
Three Traps NDA Exploits
- The "synonym-substitution" trap. One option replaces the underlined part with a synonymous phrase that doesn't fix any error. Looks like an improvement but isn't. (Example: "is married with" → "got married with" still uses the wrong preposition.)
- The "introduces-new-error" trap. One option fixes the original error but breaks something else — usually a number/tense mismatch elsewhere in the sentence. Always plug the substitution back into the full sentence.
- The "stylistic-but-not-better" trap. A substitution that sounds more "formal" but doesn't fix any actual error. If the original is grammatical, a stylistic shuffle is not an improvement. Pick (d).
Preparation Strategy
4-Week Sentence Improvement Plan
- Week 1: Patterns 1–4 (tense, conditional, preposition, S-V). 5 PYQ items / day.
- Week 2: Patterns 5–8 (modal, article, idiom, redundancy). Begin combining with Spotting Errors prep.
- Week 3: Mixed daily blocks of 10 items, half from Spotting Errors and half from Sentence Improvement. Learn to recognise the shared error categories.
- Week 4: Timed practice — 10 items in 5 minutes. Build confidence with (d) No improvement.
Drill Sentence Improvement with the Three-Option Method
NDA-pattern Sentence Improvement blocks with pattern-tagged explanations.
Start Free Mock TestFrequently Asked Questions
How many Sentence Improvement items come in NDA?
10 items per paper in NDA 2015-I to 2017-I. From 2018, the standalone block is rarer; the patterns are tested instead inside Spotting Errors and Identifying Correct Sentences.
When should I pick (d) No improvement?
When the 5-pass scan finds no error in the underlined part, none of (a), (b), (c) improves the sentence cleanly, and the original reads fluently. About 15–20% of items have (d) as the correct answer.
How is Sentence Improvement different from Spotting Errors?
Both test the same grammar. Spotting Errors asks "which part has an error?" — diagnosis only. Sentence Improvement asks "which substitution fixes the error?" — diagnosis + correction. Prep them together.
What if two substitutions both seem to fix the sentence?
Pick the simpler. NDA prefers economy. If you cannot distinguish them, prefer the option closest to the original wording (the smallest change that fixes the error).
Which NDA English topics connect to Sentence Improvement?
Spotting Errors shares all twelve error categories. Identifying Correct Sentences tests the same grammar in four-option judgment format. Direct and Indirect Speech and Parts of Speech underpin both.