Time, tense and aspect

hour glass

If you feel comfortable with the following concepts ...

time, tense and aspect
perfect, progressive, continuous, habitual, iterative, durative and prospective aspects
the distinction between progressive and continuous aspects
the distinction between stative and dynamic verb use
perfective, perfect and imperfect verb forms
telic and atelic clauses
finite and non-finite verb forms

... then feel free to use this index to go to the area that interests you.

Talking about the Present

Talking about the Past

Talking about the Future

Talking about Always

Otherwise, read on ...

Clearing some conceptual decks

Before we can look at tense forms, meaning and use in English, we have to get four things clear:

Time:

This is a non-linguistic concept of when an action or a state is set. It is non-linguistic because the relationship between time and grammatical form is often unclear with past forms used to speak about the future, future forms appearing in the past and so on.
Traditionally, we have four choices:

Now: the action / state is in the present
Past: the action / state occurred before the present
Future: the action / state will occur after the present

Tense:

This is the name we give to the form the verb takes. It refers to the form of the verb and the grammatical function of any primary auxiliary verbs involved. In English it is often averred that there are just two:

Past tense: e.g., made rather than make
present tense: e.g., comes rather than came
but we'll add a third because English most certainly does exhibit future forms (such as will go rather than goes) even if it has no 'proper' future tense signalled by an alteration in the form of the main verb as many languages do (and many don't)

Aspect:

this refers to how the user of the language views the event or how the event is experienced. There are many of these and they are signalled in languages in a bewildering number of ways. For the purposes of analysing English verb form, meaning and use, we'll focus on:

perfect: relating two times (past to pre-past, present to pre-present, future to post-future)
progressive: ongoing
continuous: current
habitual: routine
iterative: repeated
durative: long lasting
prospective: looking forward

Modality

The expression of the future is often allied to modality because, by definition, the future concerns expressions of willingness, uncertainty or duty.
Modality concerns the view that the speaker / writer wishes to convey regarding four key concepts:

the truth or otherwise of a proposition: relating to how the user of the languages perceives the likelihood of something being the case. For example, expressing doubt or certainty.
This is known as epistemic modality, from the Greek for knowledge. E.g.:
That might have been her father
obligation: relating to the language user's understanding of whether an obligation or its lack is intended to be expressed. For example, there is an external obligation, an internal sense of duty, a lack of obligation or an expression of advice.
This is known as deontic modality from the Greek for being needed. E.g.:
They shouldn't have told you that
ability and willingness: this expresses the language user's view concerning how possible it is for someone or something to do what the verb suggests or how willing they are to do it.
Because of the sense of power and willingness, this is called dynamic modality from the Greek for power. E.g.:
I couldn't safely have driven any faster
necessity: concerns the language user's view of a sense of inevitability so any statement which implies an unavoidable logical conclusion falls into this category. Essential truths about the workings of the natural world or concepts of definitions of states fall into this category.
It is called alethic modality from the Greek for truth.
If it was the colour you described, it must have been a buzzard

Here's the cut-out-and-keep guide to summarise this.

summary

Modality is not included in what follows because that is covered elsewhere in the section dedicated to modality which you can go to here.

Some examples to make this clear

Example	Time	Tense	Aspect
That'll be the postman	Now	Future simple	Continuous
That'll be the postman	he is here now	signalled by ''ll'	he is standing outside the door
I have always arrived on Sunday	Always	Present perfect	Habitual
I have always arrived on Sunday	signalled by the adverb	signalled by the form of the verb and the auxiliary	this is a routine
He thinks so	Now	Present simple	Continuous
He thinks so	this is his present state of mind	signalled by the -s inflexion	this is a current state
John is writing a book	Now	Present	Progressive
John is writing a book	this is one of his current occupations	signalled by is	this is an ongoing action
John is always banging on about it	Always	Present	Iterative
John is always banging on about it	signalled by the adverb	signalled by is	a repeated action
Murray hits a backhand down the line	Now	Present	Progressive
Murray hits a backhand down the line	commentary on current actions	signalled by -s	describing an action in progress
I have finished	Present	Present perfect	Perfect
I have finished	describing a current situation	signalled by the form of the verb and the auxiliary	the present related to the past
I leave tomorrow	Future	Present	Simple
I leave tomorrow	signalled by the adverb	signalled by base form of the verb	a one-off event
I was staying at the Ritz then	Past	Past	Durative
I was staying at the Ritz then	signalled by the adverb	signalled by the auxiliary	the state went on for some time
He's going to fall	Future	Present	Prospective
He's going to fall	signalled by the context	signalled by the verb form	event after now
What will you do if she doesn't arrive?	Future	Present	Simple
What will you do if she doesn't arrive?	signalled by the if-structure	signalled by -s	a one-off event
What would you do if she didn't arrive?	Future	Past	Simple
What would you do if she didn't arrive?	signalled by the if-structure	signalled by didn't	a one-off event

We can see from even this short list, that time, tense and aspect do not exist in a one-to-one relationship. Tenses are not, formally, tied to time and aspect is not always signalled by formal changes in the verb.

	The confusion between progressive and continuous
I think they're talking nonsense

It is unhelpful to assume that continuous and progressive are simply alternative words for the same aspect. We may, somewhat loosely, call the tense form something like present / past / perfect etc. continuous but when we consider aspect, we need to be a little more careful.
Nevertheless, it is true that in English little distinction in verb forms is made between continuous and progressive aspects so, for example:
John is working at his desk now
is progressive insofar as it refers to an action in progress, and
I am staying at The Ritz
is continuous insofar as it refers to a background state rather than an action currently in progress.
As we shall shortly see, both these aspects can be realised through apparently simple forms of the verb, although the construction with the primary auxiliary be and the present participle is the most common choice.
It is important that teachers of English are aware that other people's languages may reserve explicit verb forms to distinguish between progressive and continuous aspects.

Continuous aspect: describes a current state of affairs such as, e.g.:
    I believe in fairies
    He loves me
    He is loving the attention
    He hated me
    We are on holiday
    She is living in a guest house
etc.
The clue is in the name – the aspect refers to the speaker's perception that something is a continuing state of affairs.
The continuous aspect does not always require the auxiliary + -ing. It can be inherent in both the simple form and the auxiliary + -ing forms of the verb. This is especially true, of course, with verbs such as think, believe, understand, like etc. which contain the sense of the continuous semantically.
Progressive aspect: describes an ongoing action such as
    I'm typing this sentence
    He runs the length of the field and scores
    She is taking liberties
    We were eating in my favourite restaurant
etc.
The clue is in the name – the aspect refers to the speaker's perception that something is in progress at the time of speaking, i.e., an ongoing action.
Notice, again, that the progressive aspect does not always require the auxiliary + -ing. It can be inherent in both the simple form and the auxiliary + -ing forms of the verb. For example
    Look, I now turn over the paper and there is the shape
    Here she comes!
    I acknowledge receipt of your letter
The progressive aspect of the verb can also signal a background event which is perceived as taking place in the present but is not necessarily something being done right this minute.
Compare, for example:
    She is studying French at university
which could imply right this minute but probably refers to a background event. She may not, at the time of speaking, be anywhere near the university in question.
with
    She's in the garden, pulling up weeds
which, because of the nature of the act and the prepositional phrase, almost certainly does refer to the present moment.

The confusion between stative and dynamic

Much of the confusion evident in describing verbs as either stative or dynamic arises from the inability to distinguish between continuous and progressive aspects.

There is a distinction between, e.g.,
I am thinking
and
I think that ...
It is the distinction between the progressive aspect (I am thinking) and the continuous aspect with a simple verb form (I think). In the second of these, the verb is akin to believe (i.e., a continuous state of mind) and in the first, it describes an ongoing (that is to say progressing) action or process.

For this reason, if no other, it makes sense to speak of stative vs. dynamic uses of verbs.

Many other languages make no such distinctions between these uses of verbs and the expressions I go and I am going or I think and I am thinking are indistinguishable. English is not unique but it is slightly unusual.

The confusions between perfective, imperfective and perfect

There are three concepts here:

perfective: is the term used to indicate that an event or state is completed. For example,
    I went to Margate last Thursday
is a perfective form which may or may not have present relevance but is clearly finished.
    Napoleon died in 1821
is another example of a perfective form in English.
    I have given up smoking
is also a perfective form (because the action is completed) which happens to be in the perfect aspect as well, in this case because it has direct relevance to the present.
The perfective can be contrasted with the ...
imperfective: which is the term that indicates an event is not completed. Examples are:
She was playing tennis with John
I have lived here all my life
In neither case is the event perceived as finished. The form of the verb is described as imperfect.
perfect: is the term used to signify an imperfective or perfective which has a certain tense structure.
For example,
I have been to America
is a perfective (the act of going to America has been completed) but is a perfect tense indicating a present relevance of some sort.
I have lived here all my life
is imperfective (but still a perfect form) because it also signifies some present relevance (in this case that the state is probably (not certainly) current).
The perfect is, in English grammar, contrasted with the simple.

Many other languages, again, make no such distinctions between these uses of verbs and the expressions I went and I have been are indistinguishable. English is not unique but it is slightly unusual.
Some languages are much clearer about perfective and imperfective forms. For more on other languages, see the guide to aspect.

Telicity

This is a related phenomenon in languages.
The term telic comes from the Greek, τέλος, meaning end. The concept of telic and atelic verb phrases concerns whether an activity is seen as finished or unfinished. To grasp the point, compare:

I read the book for an hour
I read the book in an hour

Sentence 1. suggests that I did not finished the book so the verb phrase is atelic.
Sentence 2. suggests that I finished the book so the verb phrase is telic.

This matters in English because we can say:
I was reading the book for an hour
but we cannot have:
I was reading the book in an hour.

The implication for English grammar is that verbs in the perfect or continuous aspects are almost always possible with a time frame adverbial but not with a time span adverbial so. In other words, perfective forms, which are by definition telic, generally imply a time frame (even when it is not stated) but not a time span. For example:
    I had been reading for an hour
vs.
    *I had been reading in an hour
or
    I was cycling for a week
vs.
    *I was cycling in a week
or
    I have lived here for a year
vs.
    *I have lived here in a year
or
    I was reading when the telephone rang
vs.
    *I read when the telephone rang.

The situation is complicated by the fact that verbs are generally telic or atelic depending on their meaning so the phenomenon of telicity is as much semantic as grammatical. For example:

I finished the book in an hour
is telic by its meaning, because the adverbial refers to a time span, and
*I finished the book for an hour
is not possible because the adverbial refers to a time frame rather than a span.
I was cooking when the telephone rang
has the atelic verb cooking which is imperfective and the perfective rang which clearly had an end point so is telic. Compare:
I cursed when the telephone rang
in which both verbs are telic and perfective.

Some languages, for example Finnish, Estonian, Czech and Hungarian, reserve a special verb form to signal telicity but English often does it through tense aspects.

Relative and absolute tense forms

Here, we depart slightly from a traditional description of tense forms in English and take a more functional view of what the forms actually do and the meanings they realise.

Absolute tense forms: These locate an event in time relative to the here and now, i.e., the time of speaking or writing. For example:
    She will take the 6 o'clock train
sets her action as lying in the future from now.
    She caught the 6 o'clock train
sets her action in the past seen from now
    She is getting on the 6 o'clock train
sets her action in the present
    She was sitting on the train
sets the continuous state in the past
    She will be sitting on the train
sets the continuous state in the future
Relative tense forms: These take it a step further and relate what is happening relative to an absolute tense. For example:
    She has caught the train and is working on her laptop
sets the present (working) in relation to a past event (getting on the train)
    She had caught the train and was working on her laptop
sets the past (working) in relation to the pre-past (getting on the train)
    She will have finished by the time the train gets to London
sets the future (finishing) in relation to the a post-future (getting to London)
Relative tense forms do not stop there. For example:
    She was sitting on the train, reading a book
is absolute in the sense that the events are fixed in time relative to the present as we saw above.
However,
    She was sitting on the train when the she realised her mistake
sets the realising in relation to a background event and
    She had been going to work but had forgotten her laptop
sets the working as a future in the past (although one that did not happen).

An alternative way of seeing these forms is to consider what is being expressed in terms of time and the relationships between events and states, like this (following Lock, 1996: 149):

Time	Example	Explanation of the concept	Visualised green for present orange for past blue for future
The present in the present	He is working in the garden	The verb form refers to now set relative to now
The past in the present	He has worked in the garden	The verb form refers to pre-now in relation to now
The present in the past	He was working in the garden	The verb form refers to the present set in the past
The past in the past	He had worked in the garden	The verb form refers to the pre-past set in the past
The present in the future	He will be working in the garden	The verb form refers to the present set in the future
The past in the future	He will have worked in the garden	The verb form refers to the past set in the future
The future in the present	He is going to work in the garden	The verb form refers to the future set in the present
The future in the past	He was going to work in the garden	The verb form refers to the future set in the past

Seen this way, complex tenses which combine aspects can be explained conceptually. Like this:

Time	Example	Explanation of the concept	Visualised green for present orange for past blue for future
The present in the past in the present	He has been working in the garden	The verb form sets the present in the past set in the present
The present in the past in the past	He had been working in the garden	The verb form sets the present in the past set in the past
The present in the past in the future	He will have been working in the garden	The verb form sets the present in the past set in the future
The future in the past in the present	He has been going to work in the garden	The verb form sets the future in the past set in the present
The future in the past in the past	He had been going to work in the garden	The verb form sets the future in the past set in the past
The future in the future	He will be going to work in the garden	The verb form sets the future in the future
The future in the past in the future	He will have been going to work in the garden	The verb form sets the future in the past set in the future

The visualisation in colour on the right of these tables appeals to some learners. Do not present them all at once!

A third way to consider the forms is to view them from the point of view of telicity (see above).
Relative tense forms, often, refer to atelic forms so, for example:
    He will have been travelling for 24 hours
is atelic because there is no obvious end point to the activity, but
    He will travel for 24 hours
or
    He will be travelling for 24 hours
is telic because the presumption is that he will stop travelling after the 24 hours is up.

Finite and non-finite forms

In these guides, we are mostly concerned with finite verbs forms (i.e., those marked in some way for person or tense). There is a guide to finite and non-finite forms on this site.
It should not be forgotten that non-finite forms can also signal aspect, even if they do not signal time or tense. For example:

Forms	Meaning	Aspect
Feeling rather shy, he put his hand up	At the time he felt shy and at the time he put up his hand: two processes, one continuous (the feeling) and one instant (the action)	continuous and simple
Being rather a tall man, he reached it easily	Two verbs, one a permanent state (tall), the other an action (instantaneous)	continuous and simple
Arriving at station, he realised he was late	Two simple actions (arriving and realising)	simple
If you will just hear me out	Two verbs (one apparently future but actually present and referring to willingness), the other an infinitive (non-finite)	simple

Moving on

If the distinctions above are clear to you, it's time to look at the ways English refers to time and the speakers' perceptions of time.

To check that you have taken this on board, try a test.

Guides to times, tenses and aspects

In what follows this site takes a somewhat alternative view of tense grammar.

Many grammars, especially those aimed at students, start with the name of the tense, explain its formation and then list the ways in which it is used and the meanings we make with the forms. It works along the lines of, e.g.:

The present progressive is formed by taking the appropriate present tense form of the verb to be, and following it with the -ing form of the verb (omitting a final 'e' if it is present) so we get, He is having lunch with his mother.
We use this tense to talk about current actions in progress, temporary states, the arranged future and ... etc.

That is familiar to most learners and teachers and may be reassuring. However, it is a non-functional way to proceed.
It is non-functional because it presumes a mental process something like this:
mental process 1

Here, we are going to work the other way: we will start with the meanings we want to make and identify the major ways to make these meanings using verb forms and their aspects.
This assumes a mental process more like:
mental process 2