MODALS

1. CAN – COULD – (BE) ABLE TO

- Function 

  Can : to expresses ability in the present or future.

  Could : to expresses ability in the past.

  Be able to : to expresses spesific ability.

- Differences

  Can have an ability level of less than 100% while be able to have an ability level of 100%.

- Example

  a. Tegar can play the piano.

  b. Our son could talk when he was two years old.

2. MAY – MIGHT

- Function

  May :  to express possibility in the present or future.

  Might :  same as may, might is used to express possibility in the present or future.

- Example

  a. She may come here now.

  b. It might rain tomorrow.

3. MUST – HAS/HAVE/HAD TO

- Function

  Must : means that something very necessary, there is no other choice.

  Has/Have/Had To : to express the idea that something necessary.

- Differences

  Must is used much less frequently than has/have/had to in everyday speech and writing. But must have Must have a certainty level of 100% while has/have/had to have a certainty level off less than 100%.

- Example

  a. I must study to night.

  b. Rita has to go to the bank.

4. SHALL – SHOULD – OUGHT TO

- Function

  Shall : to express permission or request that used in the question sentence with subject i and we.

  Should  : to give suggestion  or advice.

  Ought to : to give advice but not compel.

- Differences

  Shall can use in the negative sentence but ought to is usually in the negative sentence.

- Example

  a. Shall we go now ?

  b. My clothes are dirty. I ought to wash them.

5. WILL – WOULD – (BE) GOING TO

- Function

  Will : to express willingness and to declare something that will happen in the future.

  Would : to express willingness and to declare something that will happen in the past.

  Be going to : to express prior plan.

- Differences

  Will have a possibility level of less than 100% while be going to have an a possibility level of 100%.

- Example

  a. Will you marry me?

  b. Tia is going to travel to Yogya tomorrow.