Common grammatical errors

Story hook

It is the 2025 Mains evaluation room. A senior examiner reads the opening line of a candidate's essay:

"The team of researchers, after analysing the data, were of the opinion that the policy have failed."

The examiner counts three errors in one sentence — subject-verb disagreement (team … were should be team … was), a comma where a period would be cleaner, and a wrong tense form (have failed should be had failed in this reported-speech context). She circles three marks on the margin and reads on.

The candidate has just lost 5 marks in 14 words — and this is his English Qualifying paper, where every mark counts toward the 75/300 threshold. Across a 3-hour paper, similar errors multiply: maybe 30-40 marks lost to grammar alone. The candidate fails to qualify.

This module is the anti-error guide. The 25 most-common slips that drain marks from otherwise good papers. Master them, and you write three hours of clean English on autopilot.

Why this matters for UPSC

Common grammatical errors are tested directly in the spot-the-error block (typically 10-20 marks of the 300-mark qualifying paper) and indirectly across the entire paper — essay, letter, précis, comprehension all lose grammar marks for the same recurring slips. Across the full qualifying paper, 30-50 marks ride on grammatical cleanliness. Mastering the 25 most common errors is the single highest-ROI prep for the qualifying paper. UPSC values it because civil service drafting is unforgiving of grammar: a Cabinet note with a subject-verb error gets sent back, and a press statement with a misplaced modifier becomes the next day's news.