Modal Verbs

 

Modal Verbs of Ability

The modal verbs of ability are CAN & COULD.

 

When we talk about general ability, we mean things we have learned to do, or things we can do. We have the ability to do them, sometimes because we have been taught or trained in a professional situation. 

We can format our code as we prefer, as we are all experienced engineers.

This example suggests that the engineers can do as they prefer because of their experience and creative freedom. They have the ability to work in their own way. 

 

We agreed that we could revisit the idea of using a linter once we had established the potential benefits.

In this example sentence, we are using indirect speech and expressing ability using could as the past of can. 

 

We could easily revisit the idea once we had established the potential benefits.

In the future, revisiting the idea would be simple. We could easily do it. Could is used as the past of can, but also for conditional or future possibility. 

Although it is not really a modal verb, we often include BE ABLE TO when we are talking about ability. This is because can is not always possible, for example, after another modal verb. Look at this example.

 

We won’t be able to revisit the idea until we’ve spent more time analysing the potential benefits.

Here we are expressing a negative; we can’t revisit the idea. Because we’re using won’t, we have to follow it with be able to. It is not possible to say won’t can. 

 

Modal Verbs of Probability & Possibility

We can do so much with modal verbs. Let’s focus on modal verbs of probability and possibility.

CAN, COULD, MAY, MIGHT, MUST, WILL & SHOULD.

These modal verbs cover a lot of options, so let’s keep it simple. 

 

IP address spoofing can be used by network intruders to overcome network security measures.

In this passive sentence, we are using can to show the ability of network intruders, but it also shows possibility. It can happen. It can be used for this purpose.

IP address spoofing may be used by network intruders to overcome network security measures.

Here we’re using may to suggest probability and possibility. It may happen, it’s possible. They probably will do it. 

 

IP address spoofing might have been used by network intruders to overcome network security measures.

In this version, the modal verb is might. We’re talking about something that was a possibility in the past. Spoofing might have been used. We’re using a perfect tense with the modal verb to suggest that it was a possibility. We’re using might as the past of may.

 

We should be able to develop the necessary comprehensive procedure regarding security flaws and default configuration.

The modal verb in this example is should. We’re using it to say that something should be possible, that there is no obvious reason to think it is not possible. The speaker is more or less sure about the possibility.

 

Modal Verbs with the Passive Voice

As we know, modal verbs can do so many things, which sometimes means they can be difficult to learn. Let’s look at something specific and start with the passive voice. 

We can use the passive voice with different modal verbs to express likelihood, ability, or obligation. We might be talking about the past, present, or future. 

We usually form passive sentences by focusing on the object and using the verb TO BE. By including a modal verb, we can convey further information. Perhaps we want to suggest necessity or possibility. Maybe we are talking about probability. 

 

This report must be done by the end of this week. 

It could be done tomorrow.

Here, we are using must, followed by be done, which forms the passive structure, suggesting the report and its deadline are the priority. 

 

We don’t need to think about who the agent is (the person performing the action) as the focus is the object, in this case the report. 

 

The response, it could be done tomorrow, uses the modal verb COULD, to show that this action is possible. It also reassures the other person that the intention is to complete the report as soon as possible. Let’s look at some more passive modal sentences.

The proxy setting can’t be bypassed. It is not possible, it can’t be done.

A good centralized log solution should have been found. Something didn’t happen, but it should have. 

The window of opportunity for an attacker must be reduced. This is vitally important. It must be done.

We expect the installation may have been finished by then. It’s a possibility. We expect it to happen.

Modal verbs are multi-use parts of everyday English. You should try them with the passive voice. It can be done.

 

Modal Obligation

When we talk about Modal Obligation, we are usually talking about firm obligation or necessity, so we think of modal verbs such as MUST. We could also be speaking about a moral obligation, or something which expresses a recommendation, such as SHOULD or OUGHT TO.

 

Let’s look at NEED, which is sometimes called a semi-modal, as it is often used as a main verb. 

As a semi-modal verb, NEED is most commonly used in the negative form and it shows that there is no obligation. Let’s take a look at an example.

The list is discarded after iterating, so it needn’t be preserved.

Here we can see there is no obligation. 

 

As a semi-modal, NEED has no past tense form, so then we would say that the list didn’t need to be preserved. There was no obligation. 

We can also use NEED to talk about unnecessary events, situations, or actions. In this case we can use a perfect construction. 

You needn’t have preserved the list, as it’s usually discarded after iterating.

In this sentence we can see that somebody performed an action that wasn’t necessary. There was no obligation. This could also be made into a passive construction.

The list needn’t have been preserved, as it’s usually discarded after iterating.

 

NEED can also be used with gerunds, both in positive and negative sentences, when there is or isn’t necessity or obligation.

The memory usage needs reducing, that’s why we have decided to make the change.

In this sentence, we can see the gerund follows NEED, expressing necessity. It needs reducing. This type of construction can be used when the speaker is giving instruction and when they believe that there is some obligation to do this.