English Grammar: An Introduction

A further function of the VP's in the two clauses in (2) is to show the relationship between the events described: the first event took place while the second one was in progress. In addition, the first VP expresses some doubt on the speaker's part through the use of the auxiliary might. In order to describe such phenomena more accurately, we need to look at the systems of the verb.

6.3.1. Tense

In terms of morphology, TENSE is a two-part system, involving a choice between PRESENT (I walk, I run) and PAST (I walk-ED, I rAn). More complex concepts like futurity and possibility are expressed through the use of auxiliaries. Tense is used to relate the events we are talking about to time in the real world. Speakers of English, in common with speakers of many other languages, seem to envisage time as a continuous line, with the speaker occupying the point "now".

In many common verbs, the past tense and past participle are irregular: he ran, he has run. There are about 200 such verbs in Modern English, but there used to be many more. This shows the force of ANALOGY in language: irregular verbs tend to become regular and new verbs have regular forms:

4a. He lit/lighted the lamp.
4b. This highli? the problem.

6.3.2. Aspect

The system of tense combines with the system of ASPECT to produce more complex forms. The basic forms are:

He goes	(PRESENT SIMPLE ASPECT)
He went	(PAST SIMPLE) There are no auxiliaries in Simple Aspects.
He is going	(PRESENT PROGRESSIVE or CONTINUOUS ASPECT, formed from an auxiliary verb and the present participle)
He has gone	(PRESENT PERFECTIVE ASPECT, formed from an auxiliary verb and the past participle)

Progressive aspect indicates the speaker's perception of the relative duration of an event. Thus in sentence (2) above, the event of "sleeping" was perceived as being of longer duration than the event of "escaping".

Present perfective aspect describes an event which was completed in the recent past. It is often combined with adverbs such as "just" or "recently". Thus we might say:

5a. Mr Jones has just left. (5 minutes before the time of speaking)

but not

5b. *William the Conqueror has arrived in 1066 AD.(naming a definite point in the distant past).

Tense and aspect can be combined in forms such as

6.3.3. Voice

The system of VOICE is a two-part system, involving a choice between ACTIVE and PASSIVE. Only transitive verbs (those which can take an object) occur in the passive.(see also 5.7)

The object of the active sentence becomes the subject of the passive sentence. The subject of the active sentence is here put into a prepositional phrase, but quite commonly it is omitted altogether.

Choice between active and passive voice can be important in stylistic terms. Consider the different effects of the following:

(7a) uses the passive voice in the two italicised parts, and sounds more formal than (7b). (7a) might occur on an official notice, while (7b) is more likely in spoken use.

In these newspaper headlines, different emphasis is placed on elements of the clauses by the choice between active and passive:

In the passive sentences, (8b) and (8c), the writer also has a choice of whether to include or omit the agent.

6.3.4. Finiteness

FINITENESS is another two-part system. Verbs are either FINITE (F) or NON-FINITE (NF). A finite verb can take a subject and shows number and tense.

The finite part is actually the auxiliary (is), which shows concord with the subject (singular), and tense (present).

In a complex verb, the first part is always the finite part.

Modal auxiliaries (see next) are followed by the infinitive, although this is not immediately recognisable because "to" is omitted. Thus in "I can swim" and "He should leave", swim and leave are infinitives. (Compare "I am able to swim" and "he ought to leave", where the infinitive is marked by "to".)

6.3.5. Modality

One of the most interesting and varied systems is MODALITY. Modal auxiliary verbs are used to express the speaker's opinion about the events described in the sentence. There are nine modal auxiliaries in all: can, could, may, might, must, shall, should, will, would. (Some grammarians include forms like ought to, dare, need among the modals but we will not be concerned with these.)

The only events we can be certain about are the events that are happening around us (the present) and events that we know have already taken place (the past). We use the modal auxiliary will/shall to refer to events in the future, ie. when we are making a prediction about an event. We also refer to the future by using a present tense, often reinforced by an adverb, or "going to". We use auxiliaries like may, might, must to express an opinion about the likelihood of something happening. Some examples are given below.

Other modals are used to express social opinions, often with the implication that the speaker has some right to advise or command the listener, as in

Modals can be ambiguous in isolation, as in this sign spotted on the London Underground:

11. Dogs must be carried.

PARAPHRASES:

If you have a dog, you must carry it.
If you go on the underground, you must carry a dog.

Modals can be combined with the systems of tense and aspect to produce subtle meanings:

12. You'll have had your tea?

If you analyse the complex verb forms, you will observe that their component parts are selected in a fixed order:

MODAL AUXILIARY + PERFECTIVE AUXILIARY + PROGRESSIVE AUXILIARY + PASSIVE + MAIN VERB:

He may have been lying. (active)
He might have been being disturbed. (passive)

Note that the modal auxiliaries have no -S suffix in the third person singular present.

6.3.6. Mood

The modal auxiliaries form part of the system of MOOD, which has three members:

INDICATIVE MOOD The mood of sentences in the past or present, ie. those stating facts.

IMPERATIVE MOOD The mood of commands, eg. "Go!" Note that predicators in the imperative mood generally have no subject.

SUBJUNCTIVE MOOD The mood of the modal auxiliaries described above. The subjunctive mood used to be expressed by inflexions; a few such forms remain as fossils in the language, as in "God save the Queen!" or "(God) bless you!" where the absence of the -(E)S morpheme in the third person singular present indicates an older subjunctive form. Such forms were quite common in Shakespeare's time, but have since been gradually replaced by modals: "Long may you live!". Subjunctives are also still sometimes used in CONDITIONAL clauses introduced by conjunctions such as if:

13a. If I were you, I'd give up.
13b. If only Hamish was/were here, he would help me.

In these clauses, what looks like a third person plural form is in fact a subjunctive.