Grammatical tense is how languages talk about time
without explicitly naming time periods
by, instead, modifying verbs to specify when action occurs.
So how many different tenses are there in a language like English?
At first, the answer seems obvious:
there's past,
present,
and future.
But thanks to something called grammatical aspect,
each of those time periods actually divides further.
There are four kinds of aspect.
In the continuous or progressive aspect,
the actions are still happening at the time of reference.
The perfect aspect describes actions that are finished.
The perfect progressive aspect is a combination,
describing a completed part of a continuous action.
And finally, there's the simple aspect,
the basic form of the past, present, and future tense,
where an action is not specified as continuous or discrete.
That's all a little hard to follow, so let's see how it works in action.
Let's say your friends tell you they went on a secret naval mission
to collect evidence of a mysterious sea creature.
The tense sets the overall frame of reference in the past,
but within that, there are many options.
Your friends might say a creature attacked their boat,
that's the past simple, the most general aspect,
which gives no further clarification.
They were sleeping when it happened,
a continuous process underway at that point.
They might also tell you they had departed from Nantucket
to describe an action completed even earlier.
That's an example of the past perfect.
Or that they had been sailing for three weeks,
something that was ongoing up until that point.
In the present, they tell you that they still search for the creature today,
their present simple activity.
Perhaps they are preparing for their next mission continuously as they speak.
And they have built a special submarine for it, a completed achievement.
Plus, if they have been researching possible sightings of the creature,
it's something they've been doing for a while and are still doing now
making it present perfect progressive.
So what does this next mission hold?
You know it still hasn't happened because they will depart next week,
the future simple.
Your friends will be searching for the elusive creature,
an extended continuous undertaking.
They tell you the submarine will have reached uncharted depths a month from now.
That's a confident prediction
about what will be achieved by a specific point in the future,
a point at which they will have been voyaging for three weeks
in the future perfect progressive.
The key insight to all these different tenses
is that each sentence takes place in a specific moment,
whether it's past, present, or future.
The point of aspects is that they tell you as of that moment
the status of the action.
In total, they give us twelve possibilities in English.
What about other languages?
Some, like French,
Swahili,
and Russian take a similar approach to English.
Others describe and divide time differently.
Some have fewer grammatical tenses, like Japanese,
which only distinguishes past from non-past,
Buli and Tukang Basi,
which only distinguish future from non-future,
and Mandarin Chinese with no verb tenses at all, only aspect.
On the other hand, languages like Yagwa split past tense into multiple degrees,
like whether something happened hours, weeks, or years ago.
In others, tenses are intertwined with moods that can convey urgency,
necessity,
or probability of events.
This makes translation difficult but not impossible.
Speakers of most languages without certain tenses can express the same ideas
with auxiliary words, like would or did,
or by specifying the time they mean.
Are the variations from language to language
just differents ways of describing the same fundamental reality?
Or do their diverse structures reflect different ways of thinking about the world
and even time itself?
And if so, what other ways of conceiving time may be out there?