Verbs: Tense

Tense is a grammatical notion that refers to the way in which a language encodes the real world notion of time. Typically this is done through endings on verbs called inflections. Verbs are the only word class that can carry tense inflections (though they don't always do so). Verbs that carry a tense ending are called finite verbs.

To refer to a verb in general terms, we usually use its base form, as in ‘the verb travel’, ‘the verb sing’. We then add inflections to the base form as required.

1. She travel+s to work by train.
2. David sing+s in the choir.
3. We walk+ed five miles to a garage.
4. I cook+ed a meal for the whole family.

It's the inflections that indicate tense. The -s inflection marks present tense. The -ed inflection marks the past tense, which is typically used to talk about past time, as in these examples (though remember that the -ed inflection can also indicate the past participle).

Present tense verb endings also indicate agreement with person. There are three persons, each with a singular and a plural form. These are shown below. (Nouns like John or dogs also belong to the 3rd person.)

Person	Singular	Plural
1st 2nd 3rd	I you he/she/it	we you they

In sentence (1), She travels to work by train, we have a third person singular pronoun she, and the present tense ending -s. However, if we replace she with a plural pronoun, then the verb will change:

• She travels to work by train. ~ They travel to work by train.

The verb travel in the example with they is still in the present tense, but its form has changed because the pronoun in front of it has changed. This correspondence between the pronoun (or noun) and the verb is called agreement.

Agreement applies only to verbs in the present tense. In the past tense, there is usually no distinction between verb forms: she travelled/they travelled. (The irregular verb be is an exception: compare she was/they were.) 

Verbs: Auxiliary verbs

A key distinction in the word class of verbs is between main verbs (also called lexical verbs) and auxiliary verbs:

• Main verbs convey the primary action, process or state.
• Auxiliary verbs are sometimes called 'helping verbs' because they work alongside main verbs to assist in creating different meanings.

These semantic descriptions are a great starting point, particularly for younger children, but older children can use more sophisticated approaches to identifying auxiliary verbs.

First, auxiliary verbs are a closed class, which means that there is a limited number of them. Unlike main verbs, auxiliary verbs can be listed relatively easily.

Here are some examples of auxiliary verbs in sentences:

• The cafe was called Steps. _{[S1A-015 #256]}
• I was wondering about that. _{[S1B-014 #92]}

You can see that the auxiliary verbs come before the main verbs that they are helping. (The main verbs here are called and wondering.)

One important role of some auxiliary verbs, the aspectual auxiliaries be and have, is to express the notion of temporal aspect: whether an event or action expressed by a verb is ongoing or completed.

• Events that are ongoing are expressed by the progressive aspect.
• Completed events are expressed by the perfect aspect.

For example:

• She is writing a play. (ongoing)
• She has written a play. (completed)

Other auxiliary verbs include do, and modal auxiliary verbs like can and should:

• Do you like pumpkin?
• I can see you.
• We should go now.

Auxiliary verbs share a number of characteristics referred to by the acronym NICE:

• Negation
• Inversion
• Code
• Emphasis

Negation

Auxiliary verbs take not or n’t to form negatives:

• We won't do it.
• They can't come.

In fact, if there isn't an auxiliary in a sentence, one must be added to make the sentence negative.

• I cry becomes I don't cry.
• I would cry becomes I would not cry or I wouldn’t cry

Inversion

Auxiliary verbs are inverted with the Subject of the sentence to form questions.

• I must eat vegetables becomes Must I eat vegetables?

Code

Sometimes a shorthand – a kind of 'code' – can be used with auxiliaries. This happens when the main verb is left out if it has been used already:

• John never sings, but Mary does [sing].

Emphasis

Auxiliaries can also be used to add emphasis.

• I do like to be beside the seaside.

The verbs be, have and do can be main verbs or auxiliary verbs. We can see this by comparing some examples.

In the next three examples they are main verbs (is, have and did are the only verbs here):

• Sarah is very friendly.
• They have three children.
• I did my exercises.

whereas in these examples they are auxiliaries helping other verbs:

• Sarah is eating a sandwich.
• They have travelled a long way.
• Did you buy anything?

Verbs: Modal verbs

Modal auxiliary verbs (or modals for short), as the name suggests, are a kind of auxiliary verb. They have most of the attributes of auxiliary verbs. They are a closed class that is identifiable as a short list, and they convey particular types of meaning.

Here is a table which lists the most important modal verbs (also called the core modals). It shows most of them in pairs as present and past tense forms, which makes them easier to remember.

present tense	past tense
will	would
can	could
may	might
shall	should
must	n/a
ought (to)	n/a

When we discuss modal verbs, we often discuss modality and modal meaning. Consider the modal verbs can, will, and must, below.

• She can go to the hospital.
• She will go to the hospital.
• She must go to the hospital.

We can radically change the meaning of the sentence simply by changing the modal verb.

In these sentences the modal verb implies different things.

She can go to the hospital.	Possibility
She will go to the hospital.	Futurity
She must go to the hospital.	Obligation

Modal verbs allows us to express different shades of meaning about statements without being long-winded. Without modals, we would have to use various other means such as maybe, if possible, it is necessary that, etc.

What do the following sentences mean?

• She can go to the hospital.
• She may go to the hospital.
• She could go to the hospital.
• She might go to the hospital.

Do they mean the same thing?

All of these modal verbs express possibility. However, they have subtly different meanings. One way to think about this is to tell yourself a story. Are there ways of continuing the sentence which make sense with one modal, but not with another?

Suppose we continue the sentence with an explanation.

• She can go to the hospital because she has a car.
• ?She may go to the hospital because she has a car.
• She could go to the hospital because she has a car.
• ?She might go to the hospital because she has a car.

Here can and could seem to be more ‘natural’ here. May and might have more of the sense of choice, and therefore appear awkward in this context.

Suppose we put in an explanation about the Subject’s choice:

• ?She can go to the hospital because she is anxious about her health.
• She may go to the hospital because she is anxious about her health.
• ?She could go to the hospital because she is anxious about her health.
• She might go to the hospital because she is anxious about her health.

Which of these sentences seem more natural now? Consider adding choose to after the modal: She can [choose to] go to the hospital. Does this make sense?

As a guideline, can and could are often better for expressing ability, whereas may and might are better for expressing choice.

For example, we might say:

• We can leave now but we may go later.

Can and may are frequently used interchangeably. Some people think that may is more old-fashioned, but it is a perfectly normal alternative to can, and more naturally expresses choice.

Can/could and may/might are present tense and past tense modal forms. Historically, could simply meant ‘can in the past’. However, this distinction is not so strict in modern English. Consider:

• He can run a mile in five minutes today.
• He could run a mile in five minutes today.
• *He can run a mile in five minutes when he was young.
• He could run a mile in five minutes when he was young.

This looks more like a strict rule: when talking about the past, use could. But you can also use could to refer to present time.

Here’s the same issue, with may and might.

• He may [choose to] run a mile in five minutes today.
• He might [choose to] run a mile in five minutes today.
• *He may [choose to] run a mile in five minutes when he was young.
• He might [choose to] run a mile in five minutes when he was young.

Again the present tense can/may seems to express future possibility relative to the present, and so does not sit well in a sentence about the past.

So far we have discussed modal verbs expressing ‘possibility’. Another group are the necessity modals, will, shall, should, and must, and the semi-modals have to, need to and ought to:

• She will go to the hospital.
• She shall go to the hospital.
• She should go to the hospital.
• She must go to the hospital.
• She has to go to the hospital.
• She needs to go to the hospital.
• She ought to go to the hospital.

Can you identify the meaning in each case? Write down your answers and discuss them in class.

Here are our answers. Did you agree with them?

She will go to the hospital.	Futurity	She will go to the hospital.
	Obligation	She is obliged to go to the hospital.
She shall go to the hospital.	Futurity	She will go to the hospital.
	Empowerment	She is enabled to go to the hospital.
She should go to the hospital.	Recommendation	It is recommended that she go to the hospital.
She must go to the hospital.	Obligation	She is obliged to go to the hospital.

Note that some of them have more than one meaning, as we have seen with can and may.

Have (to) and need (to) are sometimes called semi-modals. Unlike the core modals, they are followed by a to-infinitive. That is, we say I have to go there, but not *I have go there. Compare: I will go there, but not *I will to go there. Here are some interpretations of the semi-modals:

She has to go to the hospital.	Obligation	She is obliged to go to the hospital.
She ought to go to the hospital.	Recommendation	It is recommended that she go to the hospital.
She needs to go to the hospital.	Recommendation	It is recommended that she go to the hospital.

As with the possibility modals, the necessity modals can have different shades of meaning.

Can you see a difference between ought (to) and need (to)? Can you think of a sentence where you might use one but not the other? 

Verbs: Nonfinite and finite

Verbs can be divided into finite and nonfinite forms. Finite verbs carry tense. So, past and present tense verb forms are finite. Nonfinite verbs do not carry tense, and do not show agreement with a Subject. Put differently, they are not 'limited' by tense or agreement.

The infinitive form of a verb is nonfinite. It is the form which follows to:

to ask to believe to cry to go

to protect to sing to talk to wish

The nonfinite form is the same as the from the base form. In addition to to-infinitives, there are also bare infinitives, in which to is absent:

• Help me to open the gate! (to-infinitive)
• Help me open the gate! (bare infinitive)

The word to in to-infinitives is called infinitival to or the infinitival particle to. It is different from the preposition to.

In addition to the infinitive, there are two additional nonfinite forms:

• the present participle
• the past participle

For example:

1. The old lady is writing a play.
2. The film was produced in Hollywood.

The verb form writing in (1) is known as the present participle form. It does not agree with the Subject the old lady. If it did, it would be writes as in The old lady writes a play. Instead, the auxiliary verb is agrees with the Subject the old lady. The nonfinite present participle writing is part of a present progressive construction. This is one of the most common uses of the present participle. 

In (2), the verb form produced is called the past participle form. It does not agree with the Subject the film. Instead, the auxiliary verb was is the past tense verb related to the Subject. The nonfinite past participle produced is part of a passive construction. This is one of the most common uses of the past participle.

The -ed inflection on past participles should not be confused with the -ed inflection which is used to indicate the past tense of many verbs. For some verbs the past tense and -ed participle have the same shape (pronunciation and spelling), but the two forms are used in different ways. Compare:

1. He produced the film in Hollywood. (past tense form)
2. The film was produced in Hollywood. (past participle form)

In (1), produced is a past tense form. We could change it to present tense as in the example He produces the film in Hollywood. In (2), the auxiliary verb was is a past tense form, and produced is a past participle. We could not change produced to a present tense form, as in *The film was produces in Hollywood because it would then be ungrammatical.