Modal Forms (Part 1)

Simple Modal

I could swim at the beach.

Passive Simple Modal

The room should be cleaned once a day.

Continuous Modal

I could be swimming at the beach right now.

Passive Continuous Modal

The room should be being cleaned now.

Perfect Modal

I could have swum at the beach yesterday.

Passive Perfect Modal

The room should have been cleaned yesterday.

Perfect Continuous Modal

I could have been swimming at the beach instead of working in the office.

Passive Perfect Continuous Modal

The room should have been being cleaned but nobody was there. (Rare form)

“Can”

A. Can – general ability:

1. I can speak Chinese (PRESENT)

2. I could speak Chinese when I was a kid. (PAST – SHIFTS TO “COULD”)

3. I will be able to speak Chinese by the time I finish my course. (FUTURE – SHIFTS TO “BE ABLE TO”)

Negative Forms:

1. I can't speak Swahili.

2. I couldn't speak Swahili. (SHIFTS TO “COULD”)

3. I won't be able to speak Swahili. (SHIFTS TO “BE ABLE TO”)

B. Can – ability during a specific event:

1. With a burst of adrenaline, people can pick up cars. (PRESENT)

2. With a sudden burst of adrenaline, he was able to lift the car off the child's leg. (PAST – SHIFTS TO “BE ABLE TO”)

3. With a sudden burst of adrenaline, he will be able to lift the car. (FUTURE – SHIFTS TO “BE ABLE TO”)

Negative Forms:

1. People can't pick up cars.

2. Even the weight lifter, couldn't lift the car off the child's leg. (SHIFTS TO “BE ABLE TO”)

3. Even three men working together won't be able to lift the car. (SHIFTS TO “BE ABLE TO”)

C. Can – opportunity:

1. I have some free time. I can help her now. (PRESENT)

2. I had some free time yesterday. I was able to help her at that time. (PAST – SHIFTS TO “BE ABLE TO”)

3. I'll have some free time tomorrow. I can help her then. (FUTURE)

Negative Forms:

1. I don't have any time. I can't help her now.

2. I didn't have time yesterday. I wasn't able to help her at that time. (SHIFTS TO “BE ABLE TO”)

3. I won't have any time later. I can't help her then.

D. Can – permission:

1. I can drive Susan's car when she is out of town. (PRESENT)

2. I was allowed to drive Susan's car while she was out of town last week. (PAST – SHIFTS TO “BE ALLOWED”)

3. I can drive Susan's car while she is out of town next week. (FUTURE)

Negative Forms:

1. I can't drive Susan's car when she is out of town.

2. I wasn't allowed to drive Susan's car while she was out of town last week. (SHIFTS TO “BE ALLOWED”)

3. I can't drive Susan's car while she is out of town next week.

E. Can – request:

1. Can I have a glass of water?

2. Can you give me a lift to school?

(Requests usually refer to the near future.)

Negative Forms:

1. Can't I have a glass of water?

2. Can't you give me a lift to school?

(Requests usually refer to the near future.)

F. Can – possibility / impossibility:

1. Anyone can become rich and famous if they know the right people.

2. Learning a language can be a real challenge.

(This use is usually a generalization or an supposition.)

Negative Forms:

1. It can't cost more than a dollar or two.

2. You can't be 45! I thought you were about 18 years old.

(This use is usually a generalization or an supposition.)

“Could”

A. Could – possibility:

1. John could be the one who stole the money. (PRESENT)

2. John could have been the one who stole the money. (PAST)

3. John could be charged with the crime when the police finish the investigation. (FUTURE)

Negative Forms:

1. Mary couldn't be the one who stole the money.

2. Mary couldn't have been the one who stole the money.

3. Mary couldn't possibly be charged with the crime after the police examine the evidence.

B. Could – conditional (can, could):

1. If I had more time, I could travel around the world. (PRESENT)

2. If I had had more time, I could have traveled around the world. (PAST)

3. If I had more time this winter, I could travel around the world. (FUTURE)

Negative Forms:

1. Even if I had more time, I couldn't travel around the world.

2. Even if I had had more time, I couldn't have traveled around the world.

3. Even if I had more time this winter, I could travel around the world.

C. Could – suggestion:

1. NO PRESENT FORM

2. You could have spent your vacation in Hawaii. (PAST)

3. You could spend your vacation in Hawaii. (FUTURE)

Negative Forms:

NO NEGATIVE FORMS

D. Could – past ability:

1. I could run ten miles in my twenties.

2. I could speak Chinese when I was a kid.

Negative Forms:

1. I couldn't run more than a mile in my twenties.

2. I couldn't speak Swahili.

E. Could - polite request:

1. Could I have something to drink?

2. Could borrow your stapler?

(Requests usually refer to the near future.)

Negative Forms:

1. Couldn't he come with us?

2. Couldn't you help me with this for just a second?

(Requests usually refer to the near future.)