Grammar. expressing posibility

Possibility, probability and certainty. a

Modals

Modal verbs, sometimes called modals, are auxiliary verbs (helping verbs). They express such things as possibility, probability, permission and obligation.

Multiple Choice

Auxiliary verbs...

• Modal verb let me

• conjugate verbs

• use infinitive TO

• refers to future

• are auxiliary verbs

Modal verbs to express ability

we use can/can't for abilities in the present.

cats can see in the dark

I can't drive

We use Could/couldn't

• for general abilities in the PAST.

• WHEN I WAS YOUNGER, I COULD RUN VERY FAST.

• I COULDN'T WALK UNTIL I WAS NEARLY TWO YEARS OLD.

For ability to do something in a specific past situation, we use the negative COULDN'T, but we don't often use the affirmative could. Instead of COULD, it is usually better to use BE ABLE TO, MANAGE TO, or SUCCEED IN -ING

• We COULDN'T open the door with the key. Eventually we MANAGED TO break a window and WERE ABLE TO get in.

• 
  

FOR FUTURE ABILITIES WE USE WILL BE ABLE TO:

• My little sister WILL soon BE ABLE TO read and write.

USE BE ABLE TO FOR OTHER FORMS WHERE THERE IS NOT OPTION WITH CAN OR COULD.

• I'd like to BE ABLE TO see better.

Open Ended

What is possibility?

We use can and could to express possibility

• Use can/can't for the present and future

• could/couldn't for the past.

• be able to, especially for the past and future.

Open Ended

Passengers ____ get to London from here in 35 minutes.

Multiple Choice

We ________ discuss this at tomorrow's meeting.

• could

• couldn't

• be able to

• may

could for uncertain possibilities

• I think it COULD rain later.

Could have + past participle for uncertain past possibilities.

• I don't know where she went. I suppose she COULD HAVE GONE to the supermarket.

CAN'T/COULDN'T + BE for logical impossibility in the present and COULND'T HAVE + PARTICIPLE for the past.

• It can't be Paul at the door. He is in Japan.

• He can't have had lunch yet. It's only 11:15

Poll

Which verbs do we use to express possibility.

• can/can't/could/couldn't/could have/couldn't have

• could/couldn't/can/can't

• could have/couldn't have

Multiple Choice

Which modal verbs to we use for expressing ability:

• can/can't/could/couldn't

• managed to/be able to

• could have/couldn't have