Select the correct option for the Direct Speech conversion of the sentence below. The zoologist warned that the island’s carrying capacity might be exceeded should invasive species proliferate unchecked.

Correct — C. Going back to direct speech undoes only what reporting changed: pronouns, time words and back-shifted tenses.

Might and the inverted should are modals that reporting leaves alone, and the clause has no pronoun or time word, so it can be quoted as it stands.

The zoologist said, "The island's carrying capacity might be exceeded should invasive species proliferate unchecked." → option (c).

Why the others are wrong

• (a)
  The zoologist said, "The island’s carrying capacity will be exceeded if invasive species proliferate unchecked." — Will turns a possibility into a certainty. A direct will is reported as would, so the reported might cannot come from it. Replacing should with if is harmless.
• (b)
  The zoologist said, "Should invasive species have proliferated unchecked, the island’s carrying capacity would be exceeded." — Should invasive species have proliferated and would are forms reporting leaves unchanged, so the reported sentence would show them. It shows proliferate and might instead.
• (d)
  The zoologist said, "If invasive species proliferated unchecked, the carrying capacity had been exceeded." — Had been exceeded presents the damage as already done, where the zoologist warned of a possibility. It also drops might and the island's.

Reporting a statement after a past verb changes pronouns, time and place words, and tenses, which move one step back.

Going the other way, undo those changes and nothing else. The modals might, could, would, should and ought to do not change when reported, so they return as they are.

The inverted condition should invasive species proliferate means if invasive species proliferate, and keeps its form in both directions.

Key facts

• Might, could, would, should and ought to do not change in reported speech.
• May becomes might, and will becomes would, when speech is reported after a past verb.
• Should + subject + base verb is an inverted condition: should invasive species proliferate = if invasive species proliferate.

Common traps

• Changing might or should because the reporting verb warned is past — these modals are left as they are.
• Picking (a) because if reads more easily than the inversion — the error there is will, not if.

No directly related past PYQ was found.