C1 Grammar Challenge — Can You Spot These Subtle Mistakes?

At C1 level, students often believe grammar is no longer a problem — but even advanced learners make small errors that can lower their marks in writing or speaking.These mistakes are not about knowing the rules; they’re about noticing how native speakers really use English.

Let’s test your awareness with five tricky sentences. Try to correct them before checking the explanations.

1. “If I would have known, I’d have done something.”

❌ Incorrect

✅ Correct: If I had known, I’d have done something.

Why: Conditional sentences don’t use would in the “if” clause. Only the main clause takes would.

2. “Despite of the rain, the concert continued.”

❌ Incorrect

✅ Correct: Despite the rain, the concert continued.

Why: Despite is followed directly by a noun or -ing form, not of. (In spite of is fine, though.)

3. “I look forward to meet you soon.”

❌ Incorrect

✅ Correct: I look forward to meeting you soon.

Why: The preposition to here is part of a phrase (look forward to + noun/gerund), not an infinitive marker.

4. “He suggested me to take the train.”

❌ Incorrect

✅ Correct: He suggested (that) I take the train.

Why: After suggest, we don’t use an object + infinitive. We use a clause, often with the subjunctive (I take not I took).

5. “She has lived here since two years.”

❌ Incorrect

✅ Correct: She has lived here for two years.

Why: Since introduces a starting point; for introduces duration.

Teacher’s Insight

At advanced level, accuracy means more than avoiding big mistakes — it’s about eliminating subtle errors that reveal non-native patterns.When you edit your writing, look specifically for prepositions, conditionals, and reporting verbs.A short daily correction exercise like this can improve both your grammar precision and your confidence in writing tasks.