The role of modal auxiliary verbs is no less important than the helping and linking auxiliaries. Can, could, and may modal auxiliaries are mainly used to express possibility. And, may, might, must modal verbs used for possibility. In this article, I’m going to explain the correct use of modal verbs for possibility and certainty.
Understanding modal verbs for possibility and certainty
Modal verbs are also known as secondary auxiliary verbs. They express different moods from possibility to compulsion. Modal verbs for possibility and certainty are closely linked and sometimes overlap with one another.
Using Can, could, and may modals verbs for possibility and permission
Can, could, and may are mainly used to indicate:–
- Ability
- Possibility
- Permission
We know that these are commonly used modal auxiliaries in our daily interaction.
“Can” modals auxiliary
The first and foremost role of this auxiliary is to express,
- Ability to do something.
- It is used for both negative and positive purposes.
- Permission but to grant permission.
‘May’ is the most applicable auxiliary to ask for permission.
Unlike helping and linking auxiliaries, it doesn’t change its form according to the number and person of the subject of given sentence.
Examples of can modal auxiliary
- Students of tenth class can easily understand the basic mathematical calculations.
- Generally, tenth class students cannot write a thesis statement.
- He can ride a bike but cannot drive a car.
- Man can invent advanced technology but cannot replace the nature.
- Agriculture is the most earlier occupation. It is started prior to the iron age civilization.
- Anyone can learn it without difficulty.
“Could” modal auxiliary
Usually, it is preferred to express
- Past ability,
- Milder possibility,
- Formal request but less polite than ‘would.’
‘Can’ indicates present ability; whereas, ‘could’ is used for past ability. For possibility, ‘may’ expresses stronger possibility compare to ‘could and might.’
In order to make a polite request, ‘would’ deserves priority compare to could auxiliary. Obviously, ‘would’ is more polite than ‘could.’
- It was a hasty decision. He could wait for a better opportunity. Unfortunately, it couldn’t happen.
- Had they agreed to go for the negotiations to solve the border disputes, the devastating war could have been averted.
‘Could have’ is also used to express irreversible missed opportunity.
“May” modal auxiliary
Here, the most important use of this auxiliary is to indicate,
- Possibility in future without future auxiliary
- To ask for permission but more polite in nature.
- Compare to other modal auxiliary verbs, ‘may’ deserves priority in terms of possibility and permission.
Important examples of Modal verb may
- It may rain or may not be as we know that this is the same situation that we have been witnessing since a week.
- May I use your bike to drop my younger brother for school ?
- Today, he may be late due to heavy rain.
- In this summer, the rate of energy consumption may rise sharply compare to earlier season.
- For this, growing demand and impact of climate change may be the potential reasons.
- The crisis of food security may escalate in the coming future as the more land is being diverted for the other crops.
These are some useful examples of “can could and may modal verbs for possibility and permission.
You know that there is a lot of confusion in terms of correct use of modal auxiliary verbs just because of the ambiguous nature of some of the modals.
Here, many modal auxiliaries express same meaning but with varying degrees. Hence, we need to use them as per theirs major role. Otherwise, a lot of confusion may arise in our mind.
Understanding Modal verbs for certainty
In the process of explaining Modal verbs for possibility and certainty, Now, I’m going to explain modal verbs to express certain degree of likelihood or certainty, modal verbs like May, might, could, and must are used.
Types of degree for certainty
Generally, there are two types of auxiliaries used to express certainty of events, Modal verbs are used to describe likelihood in percentage
Verbs+ be forms are preferred for complete sense of certainty. Helping and linking verbs for complete certainty
For complete likelihood, verbs + be – is/are/will…are preferred.
Here, there is no chance for doubt. These are used for complete sense.
Modal auxiliary verbs for certainty in percentage
Following modal auxiliary verbs are used to express certainty in percent instead absolute manner.
- Near certain— Must,
- Half certain— may,
- Weak certain— might, could,
- Rarely used for present and past certainty — will/would.
Certainty means the degree of likeliness about something occur or happen in immediate present, or in near future.
1. Must modal verb for certainty
“Must” modal auxiliary is used for near certainty. In other words, when the chance of an event or situation are more to happen, must modal auxiliary is preferred.
- I think you must be free on Sunday.
- Would you help me to learn swimming, please? (but, only when he has no other assignments)
- In the first week of June, it must be hot and humid. (but, it depends on the other elements of atmosphere)
- He has just recovered from the phase of depression.
- Hope, he must have been feeling better now.
- Wow, this is so beautiful lake!
- I think, it must be pollution free for now.
2. Certainty by may modal verb
It is commonly used modal verb for possibility. But, the level of certainty it expresses is not more than half.
- It looks like that it may be our biggest mistake.
- As time passes, cyclone may lose strength.
- Once I get selected, it may prove my best achievement.
- I don’t think solar energy may prove a viable alternative for conventional energy as of now.
3. Might/could modal verbs for certainty
- She is so out spoken.
- One day, she could find herself in trouble.
- He is a risky trader.
- Very soon, he could lose all his capital.
- We have enough time, we might reach there on time.
- Now, the program might begin any time.
Apart from these modal verbs, will and would are also used to express certainty of present and past in certain situations.
This is all about the Modal verbs for possibility and certainty in detail. Importantly, modal verbs for possibility and certainty are not absolute but with certain overlapping.
Will shall would & should modal verbs
Adversative coordinating conjunctions
Simple present and continuous present
Modal auxiliary verbs explained