Advanced Grammar Polish: The Last 5% of Accuracy

At C2, grammar errors are rare but not gone. What remains are structures used so infrequently that they never get automatic — and small slips that surface under pressure.

The subjunctive after certain verbs

After verbs and adjectives of demand, suggestion, and necessity, English uses the bare infinitive — no -s, no to.

• It is essential that every applicant submit the form personally. (not "submits")
• The committee recommended that he be reinstated. (not "is")
• She insisted that the meeting start on time. (not "starts")

Triggers include: essential, vital, crucial, important + that; recommend, suggest, insist, demand, propose, require + that.

This sounds wrong to many learners because it looks like a missing -s. It isn't — it's a surviving subjunctive.

British English often prefers should in the same slot: The committee recommended that he should be reinstated. Both are correct; the bare form is more common in American and in formal international English.

The other surviving subjunctive: were

• If I were you… · She acts as though she were in charge.
• Were the decision mine, I'd delay it. (inverted, formal)
• Were it not for the funding, the project would have stopped.

Inversion after negative adverbials

When a negative or restrictive adverbial opens a sentence, the subject and auxiliary swap places.

• Not only did he meet the deadline, but he also improved the design.
• Rarely have I seen such a well-argued proposal.
• Under no circumstances should you share the password.
• No sooner had we arrived than it started raining.
• Only after the audit did they admit the error.
• Not until Friday will we know the outcome.

Triggers: not only, rarely, seldom, never, little, no sooner, under no circumstances, only after, not until.

Without inversion these sound flat or wrong: Not only he met the deadline is a clear error.

Two neighbours use the same machinery. So and such invert when fronted — So rare was the fault that nobody had documented it — and neither / nor invert automatically: I didn't know, and neither did she.

Inversion is a register signal, not decoration. It marks writing as formal, considered and slightly emphatic. In casual speech it sounds theatrical — Rarely have I seen such a mess is a joke at the kitchen table and perfectly ordinary in a report. Match it to the document, not to the sentence.

Mixed conditionals

Standard conditionals keep both halves in the same time frame. Real situations often don't.

• If I had studied medicine, I would be a doctor now. (past condition → present result)
• If she weren't so busy, she would have come yesterday. (present condition → past result)

Both are correct and common in speech, and both are frequently avoided by learners who only drilled the three "types".

Cleft sentences for emphasis

• It was the timing that caused the problem, not the budget.
• What surprised me was how quickly they responded.
• All I want is a clear answer.
• The reason it failed was that nobody tested it.

These shift emphasis without changing the facts — a hallmark of fluent, controlled writing. Fronting does a lighter version of the same job: That I don't accept. · Expensive it certainly was.

Small slips that persist

• Fewer vs. less: fewer for countable (fewer errors), less for uncountable (less time).
• Which vs. that: use which with a comma for extra information, that for defining information.
• Dangling participles: Having reviewed the data, the conclusion was obvious. → the conclusion didn't review anything. Fix: Having reviewed the data, we found the conclusion obvious.
• Comprise: the whole comprises the parts — The set comprises six items, not "is comprised of".
• Different from / to / than: from is safest; to is British and fine; than is American and disputed in Britain.

Two hypercorrections

Over-caution produces its own errors at this level:

• ❌ between you and I → ✅ between you and me (after a preposition, the object form is correct)
• ❌ He gave it to my colleague and I → ✅ …and me

And one rule worth discarding: there is nothing wrong with a split infinitive. To fully understand is standard English, and rearranging it to avoid the split usually makes the sentence worse.

Try it yourself

The quiz below targets exactly these structures — the ones that stay imperfect longest.