Error Spotting

The sentence is split into parts and exactly one part carries an error — or none does. Do not hunt at random; run the same four checks every time.

1. Subject–verb agreement. Cover every "of …", "along with …", "as well as …" phrase and read the subject straight into the verb.
2. Verb form and tense. After did/does → V1; after have/has/had → V3; after a modal → V1. Check that the tenses of the two clauses can live together.
3. Preposition and article. Is a preposition missing, doubled, or wrong? Is an article missing before a singular countable noun, or wrongly placed before a general plural?
4. Pronoun, comparison and redundancy. Case after a preposition, one comparison marker only, and no word that repeats what another word already said.

For a Marathi-medium candidate the error is very often the part that sounds perfectly fine because it is fine in Marathi: discuss about the matter, returned back, one of my friend, each of the students are, married with her, angry on me. Read those constructions with suspicion first — they are where the examiner sets the trap.

The single most common process mistake is finding two errors and choosing either one. The question guarantees exactly one, so if you find two, one of your two judgements is wrong; re-read both parts before answering.

Check in order: (1) subject–verb after striking "of …" phrases (2) verb form after did/have/modal (3) preposition and article (4) pronoun case, comparison, redundancy · exactly one part is wrong · suspect what sounds right in Marathi: discuss about, returned back, one of my friend

Find the error: (A) One of my friend / (B) is working / (C) in the Collector's office / (D) No error. → (A). "One of" selects a single item out of a group, so the group must be plural: "One of my friends". Sanity check: part (B) is right precisely because the subject is "One", which is singular, so "is working" agrees; if the error had been in (B), the sentence would have needed "are", and then two parts would be wrong at once.