Expressing Certainty English SMK

Complete certainty

The modal auxiliaries will, shall, can and must can be used to express complete certainty.

She must have reached. (I am certain that she has reached.)

You must be joking.  (I am certain that you are joking.)

There is the doorbell. That will be the postman. (I am certain that that is the postman.)

That can’t be the postman. He has already been. (I am certain that that is not the postman.)

Probability and possibility

The modal auxiliaries should, may and ought (to) may be used to express probability or possibility.

1. She should be here soon. (It is probable, not certain.)
2. I may be taking a long leave.
3. She ought to have reached.

Weak probability

To express weak probability, we can use might or could.

1. He might win.
2. You could be a millionaire one day.

Theoretical or habitual possibility

To express theoretical possibility we can use can.

1. Glass can be blown.
2. Mumbai can be very warm in April and May.

Conditional possibility

1. If you had worked hard, you would have passed.
2. If you invited, she would come.
3. If you just stopped talking, I could get some work done

Example :  

    1. Asking and giving for certainty

      Anisa               : Are you sure it’s going to rain?

     Bambang         : I’m positive. The sky is so cloudy.        

   2. Expressing uncertainty/doubt and respond to doubt

       Teacher          : Can you do this exercise?

       Bona               : I’m not sure

       Teacher          : Come on, Sure you can.

Asking for certainty

1. Are you sure
2. Really
3. Do you think so
4. Are you certain 
5. Is it confirmed
6. Is ok if…..?

Giving for certainty

1. I’m certain
2. Of course
3. Certainty
4. No doubt about it
5. Trust me
6. Absolutely sure

Expressing to doubt/uncertainty

1. I'm not sure
2. I doubt it
3. Well I dont know

Responding to doubt

1. Come on
2. Take it easy
3. Don't worry