Defective Verbs in English
Watch the video, read the lesson, and do the exercises:
In grammar, “defective” describes words that do not follow all the rules of the class of words to which they belong.
Defective verbs in English are verbs which do not have all the usual verb forms. These verbs cannot be used in some of the ways that normal verbs can.
Native English speakers do not normally learn about defective verbs. It is more common to study irregular verb forms (for example: eat, ate, eaten) and exceptions to the rules.
There are not many defective verbs in English, and most of these verbs were not originally defective. Some verbs are becoming more defective as time goes on. We will look at examples of these verbs in this lesson.
To understand defective verbs, you must first understand the normal uses of a regular verb.
For example, let’s look at the regular verb “learn”. Learn is not a defective verb. You can use it in any mood or tense.
- I learn
- I learned
- I have/had learned
- I shall/will learn
- I shall have learned
- I may/can/must learn
- I am learning
- I will be learning
- I have been learning
- I will have been learning
- Learn! (imperative)
On the other hand, “can” is a defective verb. Can cannot be used in all moods or tenses. You can say I can and he/she can, but you cannot say I have/had can or I will can.
There is also no future form of can. For this form, you have to use some form of “to be able” plus an infinitive (go, run, sleep, etc.).
Examples: I will be able to pick you up if I know what time the train arrives.
Can also lacks an imperative (command). You can tell someone to go, sit, or speak, but you cannot tell someone to can.
Common Defective Verbs
There are only a few defective verbs in English. Many of these are modal verbs (identified with a *). These are the most common defective verbs in English.
- am
- been
- begone
- beware
- can*
- could*
- may*
- might*
- must*
- ought*
- shall*
- should*
- was
- will*
- would*
These verbs are defective because there is no infinitive, gerund/present participle, or past participle.
Learn more about English Modal Verbs with this step-by-step series: English Modal Verbs.
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Irregular Verbs Are Not Defective Verbs
A defective verb is a verb that cannot be used in all moods or tenses.
Irregular verbs have all moods and tenses, but are irregularly formed.
Regular verbs consist of three main parts (root/present, simple past, and past participle). Regular verbs have an -ed added to the end of the root verb for both the simple past and past participle.
Irregular verbs do not follow this pattern, but that does not make them defective. Irregular verbs can still be used in all moods and tenses.
Examples:
- eat, ate, eaten
- feed, fed, fed
- begin, began, begun
- know, knew, known
- drink, drank, drunk
- bite, bit, bitten
Practice
Part A: Choose the correct modal verb to complete each sentence.
- ____________ (Can/Would) I borrow your pencil?
- I ____________ (shall/could) sing well when I was in high school.
- The actor ____________ (will/ought) audition today.
- If you are interested in becoming a teacher, you ____________ (should/will) attend a university.
- I cannot find my glasses. I ____________ (will/might) have left them in the bathroom.
- Last night, I ____________ (shall/could) relax because I didn’t have to work.
- The children ____________ (must/would) go to bed early because they have school tomorrow.
- ____________ (Would/Must) you loan me some money?
- You ____________ (would/ought) to find a new job.
- You ____________ (must/should) be 16 before you can apply for a license.
Part B: Choose the correct verb form to complete the story.
Tim and Susan were/was walking to school one morning when something catched/caught Tim’s eye. He had saw/seen something blue sticking out from underneath a bush. He knelt/kneeled down to look at the object. It was/were a wallet! Someone must/should have lose/lost it! Tim stuck/sticked his hand under the bush and gotten/got the wallet.
“There is a lot of money in here,” he tell/told Susan. He holded/held the money in his hand.
“We might/should return it,” Susan said/say. She saw/seen a driver’s license. She read/readed the name and address aloud. “This address is/be very close to here. We should/would go there now.” She slided/slid the license back into the wallet.
Tim putted/put the money back in the wallet. He known/knew what he had to do. They could/must return the wallet to the man.
Tim and Susan finded/found the man’s house. Susan ring/rang the doorbell. The man came/comed to the door.
Tim speaked/spoke first. “We found/finded your wallet.”
The man’s eyes lit/light up. “Thank you for returning my wallet! I thinked/thought it was gone forever” The man were/was so happy. “You ought/must to be proud of yourselves for doing the right thing,” he says/said.
The man digged/dug into the wallet and withdrawn/withdrew two 20 dollar bills. He handed the money to the kids and shaked/shook their hands. The children was/were glad that they had chosen/choosed to return the wallet.
Answers
Part A:
- Can I borrow your pencil?
- I could sing well when I was in high school.
- The actor will audition today.
- If you are interested in becoming a teacher, you should attend a university.
- I cannot find my glasses. I might have left them in the bathroom.
- Last night, I could relax because I didn’t have to work.
- The children must go to bed early because they have school tomorrow.
- Would you loan me some money?
- You ought to find a new job.
- You must be 16 before you can apply for a license.
Part B:
Tim and Susan were walking to school one morning when something caught Tim’s eye. He had seen something blue sticking out from underneath a bush. He knelt down to look at the object. It was a wallet! Someone must have lost it! Tim stuck his hand under the bush and got the wallet.
“There is a lot of money in here,” he told Susan. He held the money in his hand.
“We should return it,” Susan said. She saw a driver’s license. She read the name and address aloud. “This address is very close to here. We should go there now.” She slid the license back into the wallet.
Tim put the money back in the wallet. He knew what he had to do. They must return the wallet to the man.
Tim and Susan found the man’s house. Susan rang the doorbell. The man came to the door.
Tim spoke first. “We found your wallet.”
The man’s eyes lit up. “Thank you for returning my wallet! I thought it was gone forever...” The man was so happy. “You ought to be proud of yourselves for doing the right thing,” he said.
The man dug into the wallet and withdrew two 20 dollar bills. He handed the money to the kids and shook their hands. The children were glad that they had chosen to return the wallet.
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