A) WILL and WON’T are used to express what we believe or guess to be true about the present. They indicate an assumption based on our knowledge of people and things, their routines, character, and qualities. Example: “I wonder what my husband is doing”. “Well, it’s Saturday night, so I guess that right now he’ll be dancing with a blonde woman at the disco.” Example: “Someone’s knocking at the door, but it’s so late!” “That won’t be the postman.
B) MUST is used to express the most logical or rational interpretations of a situation. We do not have all the facts, so it is less certain than WILL. Example: Alf is a very good tennis player and not many players beat him. But yesterday he played against Bill and Bill won. So:
“Bill must be a very good player “(otherwise he wouldn’t have won). The negative of this use is CAN’T. We use can’t to say that we think something is impossible.
Example: “You’ve only just had dinner. You can’t be hungry already. “(It is impossible that you are hungry).
C) SHOULD is used to express what may reasonably be expected to happen. This use of SHOULD has the idea of if everything has gone according to the plan.
Example: “This homework shouldn’t take you too long. “(if you ´ve understood what you have to do.)
“Our guests should be here soon. “ (If they haven’t got lost)
D) MAY is used to express the possibility that an event will happen or is happening. Example: “You are looking for Jack. Nobody knows for sure where he is but you get some suggestions. He may be in his office.” “Where’s Ann?” “She may be having a bath, I don’t know.”
E) MIGHT is more tentative and slightly less certain than MAY. Example: “It might rain. Take your umbrella.”
F) COULD has a similar meaning to MIGHT.
Example: “You could be right. I’m not sure”
G) COULDN’T has a similar meaning to CAN’T but is...