SPECULATION
EGP #1239 | C2 | MODALITY / could Can use 'couldn?t have' + '-ed' to speculate about the past. Lexical range: N/A
他不可能没关车窗——进屋前我亲自检查过的。
He ___couldn't ___have ___left the car window open — I checked it myself before we went inside.
他们不可能事先知道答案——题目是今天早上才出的。
They ___couldn't ___have ___known the answer beforehand — the question was only written this morning.
你不可能听到门铃声——门铃电池上周就坏了。
You ___couldn't ___have ___heard the doorbell — the battery has been dead since last week.
她不可能一个晚上就写完这份作业——通常需要整整一周。
She ___couldn't ___have ___finished the assignment in one evening — it normally takes a full week.
他不可能忘了你的生日——他上周还提到了。
He ___couldn't ___have ___forgotten your birthday — he mentioned it just last week.