We use will for something in the past that we are very certain happened.

Sandra must have forgotten about our appointment. I can’t have wished ill of another person.īelow is a sample scenario using modals of deduction and speculation in the past. You may / may not have done the dishes this morning. They could have finished the training if not for the technical issues. She might / might not have registered for the seminar. Put together modals of deduction and speculation must, might, could, may, can’t and have and then a past participle verb to deduce and speculate about an action that occurred in the past. Incorrect: Mom can be at the supermarket.

We do not use can to talk about specific possibilities.Ĭorrect: Mom could be at the supermarket.

The cost of living can be very high in big cities.

We use can for something that is generally possible, something we know sometimes happens.

Incorrect: The temperature should be too high today.

Instead, it’s a better idea to use will.Ĭorrect: The temperature will be too high today. This use of should isn’t usually used for negative events.We use should and shouldn’t to make an assumption about what is probably true, if everything is as we expect.We use will and won’t when we are very sure.(fairly sure this isn’t true) Note that in this case, the opposite of ‘must’ is ‘ can’t’.

You ask Danny this question: Where is Amanda? You are waiting for Amanda with another friend, Danny. Know the proper modal to use depending on how true you think that an action occurs. Deducing and speculating about the presentĬombine modals of deduction and speculation must, might, could, may and then an infinitive verb to deduce and speculate about an action that happens in the present.īelow is a sample scenario using modals of deduction and speculation in present. We choose the verb depending on how sure we are. Use modals of deduction and speculation when we want to make a guess about something.

What modals