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Console the exhausted university student! She just drank six espressos and stayed up all night to memorize her textbook, only to find a "Class Canceled" sign on the door this morning.
Select ALL the grammatically correct sentences that accurately describe her tragic situation using past modals.
The correct answers are: She needn't have memorized the entire textbook. She could have been sleeping peacefully in her warm bed instead. She must have been fuming when she finally saw the sign on the classroom door.
- Needn't have + past participle is the perfect way to express that someone did something, but it turned out to be completely unnecessary!
- Could have been + verb-ing expresses an alternative continuous action that was possible in the past but didn't happen.
- Must have been + verb-ing is a strong logical deduction about a past continuous state or action.
Why the others are wrong:
Needn't is a modal auxiliary and is followed directly by the bare infinitive (have), never by to have. The continuous form requires a present participle (sleeping), not a past participle (slept).