... Unit 5: Possibility and Probability Perfect Modals I. Possibility: May, Might & Could:1.May, Might are used to for the ... or could notImpossibility (negative only)Ex: That couldn’t be true!Note: We often use phrases like I think, I should think, I suppose, I guess, I reckon, etc…before may, might and could to ... work today.II. Probability: Must & Can’t:1.Must: something is certainly true.Ex: Mary isn’t in class. She must be sick. (Present only). In negative sentences both must not and don’t have...