Change the following from active to passive: Historians may well reinterpret the artifact after new evidence emerges.

Correct — A. A modal verb goes into the passive as modal + be + past participle.

may well reinterpret → may well be reinterpreted
the artifact (object) → subject
historians (subject) → by historians

The time clause after new evidence emerges stays unchanged → option (a).

Why the others are wrong

• (b)
  The artifact may have been reinterpreted by historians after new evidence emerges. — may have been reinterpreted is the passive of may have reinterpreted, a possibility about the past. The original looks ahead, after new evidence emerges, and this option also drops well.
• (c)
  The artifact will be reinterpreted well by historians after new evidence emerges. — will replaces may, turning a possibility into a certainty. Moving well after reinterpreted also changes it: reinterpreted well means reinterpreted skilfully, not likely to be reinterpreted.
• (d)
  The artifact could well be reinterpreting by historians after new evidence emerges. — be reinterpreting is an -ing form, so the verb is not passive at all. The passive needs the past participle reinterpreted, and could has also replaced may.

In the passive, the modal stays and be + past participle follows it: must be delivered, should be cleaned, may be reinterpreted.

May well says that something is quite likely. Well is part of that phrase, so it stays straight after may: may well be reinterpreted.

The object of the active verb becomes the subject, and the old subject moves into a by-phrase.

Key facts

• Passive with a modal: modal + be + past participle, as in must be delivered.
• Passive with a perfect modal: modal + have been + past participle, as in could have been sent.
• May well, might well and could well mean that something is likely: It may well rain.

Common traps

• Picking may have been reinterpreted because it looks fuller, when have moves the action into the past
• Moving well to the end, which changes likely into skilfully
• Accepting be + -ing as a passive form

No directly related past PYQ was found.