You know the grammar rules and still get it wrong. Here is why

There is a specific kind of frustration in English preparation that more revision does not touch: the rules are clear when you study them, and then the mock says otherwise.

Both doubts below are versions of that. Neither needed more grammar.

The concept is clear in study and gone in the exam

Even after learning all grammar rules, everything goes wrong in mocks. Concept feels clear in study but doesn’t click in the exam.

Error Detection mein rules yaad hone ke bawajood mock mein sab galat ho jaata hai. Concept clear lagta hai lekin exam mein pakad mein nahi aata.

Knowing a rule, and applying it correctly under time pressure with four similar-looking parts and a “No Error” option sitting there tempting you to overthink, are genuinely two different skills. Most study routines only build the first one.

So the fix is not more revision. It is an error log.

After every mock, go back to each Error Detection question you got wrong and write one line against it. Not the correct answer — the reason:

• Concept gap — you did not actually know the rule.
• Silly error — you knew it, and rushed.
• Time-pressure error — you reached it too late to think clearly.

Three categories. One line per question. That is the whole system, and it is deliberately this small so that you actually keep it.

Do it honestly for even eight to ten mocks and something usually becomes obvious: it is the same two or three rules repeating, or the same type of mistake repeating across different rules. Those are very different problems with very different fixes, and you cannot tell them apart from a score.

Once you can name the actual pattern, fixing it takes far less time than learning the rule did the first time.

Strong overall, but one question type keeps failing

Overall English is strong, but “match the following with grammar correction” type questions get skipped or wrong.

Overall English strong hai, “match the following with grammar correction” type questions hi chhoot jaate/galat hote hain.

This is a genuinely different question format, which is why a strong overall base does not automatically carry over.

Error Detection asks you to find a mistake in isolation. This format asks you to match a phrase to its single correct grammatical replacement among several close-looking options. That tests precision, not just recognition. It is a narrow, learnable skill — not a sign of a weak foundation.

Treat it as its own topic:

Pull this exact question type out of the last five to six years of Prelims and Mains papers, and drill only that. Ten to fifteen minutes daily, nothing else mixed in, until the pattern of what makes one option more correct than another becomes familiar.

Most candidates see this stop being a problem within two to three weeks of that kind of focused, isolated practice. The reason it works is the same reason the error log works: you are practising the specific thing that is failing, instead of practising English in general and hoping the specific thing improves along the way.

What both answers have in common

In both cases the gap was not knowledge. It was the distance between knowing something and executing it under exam conditions — and that distance closes only with practice aimed directly at it.

That is worth remembering the next time a score drops and the instinct says revise the chapter again. Sometimes the chapter is fine.