4 Circle the correct modal verb of probability in the sentences about Jane and the Fletchers. 1 The Fletchers must be / can't be Jane's neighbours. 2 Jane must have / may have three sons. 3 The Fletchers can't be / could be a retired couple. 4 Jane must know / might know about the new law. 5 Jane may be / can't be thinking of consulting a lawyer. 6 The Fletchers must have / can't have children of their own living at home. Read the original letters on p90