🕵️ Grammar B2-7: Modals of deduction and speculation

At B1 you learned to deliver verdicts about the present — must for one surviving answer, might / may / could for several, can’t for an answer the evidence rules out. This material bolts a second axis onto that scale: time. One grid of six cells holds the whole system — must be and must have gone, might be waiting and might have been waiting, can’t be and can’t have driven — and the two questions that fill it are always the same: what does the evidence allow, and is the mystery now or already finished? Along the way the material exiles mustn’t have from the certainty scale where learners keep planting it, separates the strong no (couldn’t have) from the weak no (might not have), and insists that a verdict without a piece of evidence behind it is a bluff a reader can hear. Thirty-two multiple-choice items, a ten-chip now-or-then sort, six corrections and six reveal cards drill the movement around the grid, and a mini-mystery in a Monday-morning office lets the reader deduce alongside the narrator.