Spotting Errors and Sentence Improvement

Error-spotting and sentence improvement are among the highest-frequency NDA GAT English question types. They test the same grammar rules repeatedly, so a checklist approach scores fast and reliably.

Core ideas

The task: identify the part of a sentence with an error (or the best replacement). The errors cluster into predictable categories:

• Subject–verb agreement: singular subject with plural verb or vice versa.
• Tense consistency: wrong or mixed tenses.
• Prepositions: 'married to' (not with), 'good at', 'differ from', 'consist of', 'capable of'.
• Articles: a/an by sound (an hour, a university), 'the' for unique things.
• Pronoun agreement: pronoun must match its noun in number/person.
• Degree of comparison: 'than any other' (not 'than any'), no double comparatives ('more better').
• Redundancy: 'return back', 'repeat again', 'free gift'.

Exam Tricks & Tips

• 🎯 Run a fixed checklist per sentence: agreement → tense → preposition → article → pronoun → comparison.
• 🎯 'a/an' is decided by SOUND, not spelling: 'an hour', 'a European', 'an MP'.
• 🎯 Watch prepositions with fixed verbs: differ FROM, superior TO, married TO, comprises (no 'of').
• 🎯 Reject double comparatives/superlatives — 'more easier', 'most cleverest' are always wrong.
• 🎯 Spot redundancy: 'return back', 'reason is because', 'free gift' carry a hidden error.
• ❌ Common mistake: assuming 'no error' too readily. NDA plants a subtle preposition or agreement slip in most such sentences — recheck the small words.

Expected exam pattern

Sentences split into parts (A/B/C/D); pick the erroneous part, or choose the best improvement for an underlined phrase. Agreement, prepositions and tense dominate.

Quick recap

Apply a checklist: subject–verb agreement, tense, preposition, article (a/an by sound), pronoun agreement, comparison, redundancy. Fixed-preposition verbs and double comparatives are the most-tested traps; don't over-choose 'no error'.

Cover, recall, check. 11 cards on common errors.

Q1. What decides 'a' vs 'an'?
A1. The sound of the next word, not its spelling (an hour, a university).

Q2. Correct preposition: 'differ ___'?
A2. differ FROM (something/someone).

Q3. Correct preposition: 'superior ___'?
A3. superior TO (not 'than').

Q4. Correct preposition: 'married ___'?
A4. married TO.

Q5. What is wrong with 'more better'?
A5. Double comparative — use just 'better'.

Q6. Error type in 'return back'?
A6. Redundancy — 'back' is superfluous.

Q7. Comparison: 'taller than any ___ boy'?
A7. 'than any OTHER boy'.

Q8. Verb for 'The team ___ playing well'?
A8. 'is' — collective noun as a unit.

Q9. 'consist ___'?
A9. consist OF.

Q10. A quick error-check checklist order?
A10. Agreement → tense → preposition → article → pronoun → comparison.

Q11. Error in 'The reason is because he was late'?
A11. Redundant — use 'The reason is that…'.

Spotting Errors and Sentence Improvement are the highest-volume grammar formats in NDA English — the same rules, tested by hunting for a flaw or upgrading a phrase.

Core idea / what this tests: Detecting grammatical errors in a divided sentence, and selecting the best replacement for an underlined part.

Deep explanation

Beginner — The two formats

• Spotting Errors: a sentence split into labelled parts (A/B/C/D); choose the part containing an error (or "No error").
• Sentence Improvement: an underlined phrase with four alternatives; pick the grammatically best version (one option repeats the original for "No improvement").

Intermediate — The high-frequency error types

Scan for these systematically:

• Subject–verb agreement (singular subject, plural verb or vice versa).
• Tense consistency (an unjustified shift between past and present).
• Prepositions (wrong pairing: "married to", "different from", "capable of").
• Articles (a/an/the misuse or omission).
• Pronoun agreement (number/gender mismatch with the antecedent).

Advanced — Subtler traps

• Parallelism: items in a list must share the same grammatical form ("reading, writing and to speak" is wrong → "speaking").
• Comparatives: "than" for comparisons, no double comparatives ("more better").
• Redundancy: "return back", "reason is because", "each and every" often flagged.
• Misplaced modifiers: the modifier must sit next to what it describes.

Worked example

Spot the error: "One of the boys / who came late / were punished / by the teacher."
The subject of the main clause is "One" (singular), so the verb should be "was", not "were". The error is in part C ("were punished") → "was punished".

NDA relevance

Together these two formats can account for a dozen or more marks. Because the underlying rules overlap with the grammar and vocabulary topics, mastering agreement, prepositions and parallelism pays off across the whole English section.

Exam tricks & shortcuts

• Read the whole sentence first for sense, then check each part against a mental rule-list.
• Isolate the true subject and match its verb — the single most productive check.
• For prepositions, rely on fixed collocations you have memorised.
• If nothing is wrong after a careful pass, confidently choose "No error / No improvement" — it is sometimes correct.

Worked Example

Problem: Spot the error and rewrite the sentence correctly:
"One of the students (A) / have not (B) / submitted their assignment (C) / on time (D)."

Solution:
Examine the grammatical subject. The phrase "One of the students" has its true subject as "One," which is singular; "of the students" is only a prepositional phrase describing which one. A singular subject requires a singular verb.

• Part (B) "have not" is a plural verb form. With the singular subject "One," it must be "has not." So the error is in part (B).
• Part (C) also has a pronoun issue: "their" (plural) refers back to singular "One," so it should be "his/her" for strict agreement.

Corrected sentence: "One of the students has not submitted his (or her) assignment on time."

Answer: Error is in part (B) — "have not" should be "has not" (with "their" best changed to "his/her").