Tense - finite and infinite verbs
Examine the verbs to swim, to take, to study. Such verbs give no indication of time so we say that they are infinite (i.e. time-less) verbs. We call them infinitives. Every English verb has an infinite form.
When we are speaking or writing, we usually wish to indicate whether an action took place in the past, is taking place in the present or will take place in the future. In some languages, the time setting is simply shown by adding modifiers to an infinitive – saying something like We (to) swim yesterday or We (to) swim tomorrow. However, in English, we use different forms of the verb itself as the main way of indicating different time settings. These different forms of the verb are called inflections. (The Latin flecto means 'to bend', as in flexible). Examine the following sequences:
- She swam yesterday, she is swimming today and she will swim tomorrow.
- I took a tablet yesterday, I am taking one now and I will take one tomorrow.
- They studied yesterday, they are studying now and they will study tomorrow.
Notice that the verbs have been changed (inflected) slightly to indicate different locations in time: the past, present and future. As well, auxiliary verbs (helping verbs such as is, will, am, are) have been used. As the verbs above have a location in time, they are called finite verbs.
While modifiers such as yesterday, today and tomorrow are often used to give a more precise location in time, in English the verb still has to be inflected to show either past, present or future tense.
The word tense comes from the Middle English word tens, meaning time. In English, the main way of placing an action in time (i.e. to show whether the tense, the time setting, is past, present or future) is by varying the form of the verb. One of the main jobs of verbs in English is to indicate tense.
Aspect
Related to tense is the concept of aspect. There are three tenses - past, present and future - and in each of those tenses, we can look at events as if they have been completed (perfect aspect); or we can view them as continuing over a period (imperfect aspect) … or we can be indefinite (simple aspect). Thus, there are three tenses with three possible aspects. Not surprisingly, controlling tense and aspect is one of the big challenges in English because there are nine variables. The nine possible combinations are modelled below.
| Past tense | |
|---|---|
| simple aspect (indefinite): | He slept at Nick's place. |
| imperfect aspect (continuous): | He was sleeping when the storm hit. |
| perfect aspect (completed): | He had slept soundly. |
| Present tense | |
|---|---|
| simple aspect (indefinite): | He sleeps soundly most nights. |
| imperfect aspect (continuous): | He is sleeping at Nick’s place tonight. |
| perfect aspect (completed): | He has slept through the storm. |
| Future tense | |
|---|---|
| simple aspect (indefinite): | He will sleep at Nick’s place. |
| imperfect aspect (continuous): | He will be sleeping at Nick’s place. |
| perfect aspect (completed): | He will have slept at Nick’s place that night. |
Number
In English, the verb needs to agree with the subject in number. Singular subjects (just one item) need a singular verb and plural subjects (more than one item) need a plural verb. This is most obvious in the present tense. If we convert the present tense model sentences above so that the subject becomes plural, the verbs change like this:
- He sleeps... (singular) → They sleep... (plural)
- He is sleeping... (singular) → They are sleeping... (plural)
- He has slept... (singular) → They have slept... (plural)
If you convert those examples to past and future tenses, you will see that the same verb often works for both singular and plural subjects... but not always.
Modality
Our writing and speaking are full of shades of meaning, including the strength with which we assert things, the varying levels of possibility, certainty and commitment to positions and statements. For example, if we are talking about our time of arrival somewhere, we might say:
- 'We might arrive by tomorrow' or
- 'We ought to arrive tomorrow' or
- 'We must be there by 4.00 p.m. or we will miss the flight!'
The verbs in those statements indicate different modality, different degrees of certainty, ranging from low modality (might) to high modality (must). While we can vary verbs to alter modality, we can also achieve the same modal differences by using different adjectives, adverbs and nouns. For example, varying the adjective, we might say:
- It is possible that I will arrive tomorrow.
- It is probable that I will arrive tomorrow.
- It is certain that I will arrive tomorrow.
Again, using adjectives, we might discuss the possible cause of an accident, the probable cause of an accident, the definite cause of an accident. Changing the adjective changes the modality of a statement. Similarly, the degrees of comparison of adjectives have an influence over modality: for example, something might be likely, or more likely or most likely!
The choice of adverbs can influence the modality. We can indicate that an accident was perhaps or conceivably caused by faulty brakes, probably caused by faulty brakes or certainly caused by faulty brakes.
Nouns can function in the same way. We can discuss the possibility that an accident was caused by faulty brakes, the probability that it was caused by faulty brakes or the certainty that it was caused by faulty brakes.
In academic writing, the continual use of low modality language is called hedging. It is cautious language, where conclusions are not dogmatically stated but rather stated as possibilities rather than certainties. Deciding on the appropriate level of modality is an important part of writing and speaking and establishing credibility.