Modal verbs combine with the passive voice (be + past participle) and perfect forms (have + past participle) to create a wider variety of meanings. These constructions frequently appear on examinations.
Basic Rules
Modal verb + passive voice: modal verb + be + past participle
Examples include “will be done / can be done / must be done / should be done.” They mean “will be done / can be done / must be done / should be done.”
Example: “This problem can be solved easily.（This problem can be solved easily）”
Modal verb + perfect form: modal verb + have + past participle
Conjecture or regret about the past (studied in the previous lesson).
Modal verb + perfect form + passive voice: modal verb + have been + past participle
Examples include “must have been done / may have been done / should have been done.” “The document must have been lost.（The document must have been lost）” “This should have been done earlier.（This should have been done earlier）”
At the high-school level, it is important to recognize these multilayered structures. The sentence pattern remains SV (passive); only the verb phrase has become longer.
The meeting will be held tomorrow.（The meeting will be held tomorrow）← will + passive voice
This rule must be followed by everyone.← must + passive voice
The window may have been broken by the wind.（The window may have been broken by the wind）← may + perfect + passive
More care should have been taken.（More care should have been taken）← should + perfect + passive
The bridge cannot have been built in just one year.← cannot + perfect + passive
Points to Remember
① Choosing between modal + passive voice and active voice: When translating an active sentence from another language into English, the passive voice is often more natural in English.
- “Even a child can read this book” → This book can be read even by a child.
- “More effort should have been made” → More efforts should have been made.
② Passive progressive voice + modal: “be being + past participle” can theoretically be combined, but it is rare. “The road should be being repaired.” is unnatural, so use a form such as “The road is currently being repaired.”
③ Priority in combining forms: modal verb → have → be → -ing → past participle. “will + have + been + being + done” is the theoretical maximum length, but “should have been done” is common.
④ Negative form: Place not immediately after the modal verb.
- will not be done
- may not have been done
- should not have been told
⑤ Questions: Move the modal verb to the beginning of the sentence.
- Will it be done by Monday?
- Could it have been forgotten?
- Modal verb + passive voice: modal verb + be + past participle
- Modal verb + perfect form: modal verb + have + past participle
- Modal verb + perfect + passive: modal verb + have been + past participle
- Order: modal verb → have → be → past participle
- In negative forms, place not immediately after the modal verb
Practice
- Translate “This problem should be considered carefully” into English using should + passive voice.
- Translate “The window must have been broken by someone” into English using must have + passive voice.
- Rewrite “A decision should have been made earlier” using should have + passive voice (decision).