# Lojban Wave Lessons/Tense and aspect

## Lesson 9: sumtcita

So far we have been doing pretty well with the selbri we have had at hand. However, there is a finite amount of defined selbri out there, and in many cases the sumti places are not useful for what we had in mind. What if, say, i want to say that I am translating using a computer? There is no place in the structure of fanva to specify what tool I translate with, since, most of the time, that is not necessary. Not to worry, this lesson is on how to add additional sumti places to the selbri.

The most basic way to add sumti places are with fi'o SELBRI fe'u (yes, another example of a famyma'o, fe'u. It's almost never necessary, so this might be the last time you ever see it.)

In between these two words goes a selbri, and like lo SELBRI ku, fi'o SELBRI fe'u extracts the x1 of the selbri put into it. However, with fi'o SELBRI fe'u, the selbri place is converted, not to a sumti, but to a sumtcita, meaning sumti-label, with the place structure of the x1 of the selbri it converted. This sumtcita then absorbs the next sumti. One could say that using a sumtcita, you import a sumti place from another selbri, and add it to the bridi being said.

Note: Sometimes, especially in older texts, the term tag or modal is used for sumtcita. Ignore those puny English expressions. We teach proper Lojban here.

While it is hard to grasp the process from reading about it, an example can perhaps show its actual simplicity:

skami = x1 is a computer for purpose x2
pilno = x1 uses x2 as a tool for doing x3

mi fanva ti fi'o se pilno {fe'u} lo skami {ku}{vau} - I translate this with a computer The x2 of pilno, which is the x1 of se pilno is a place structure for a tool being used by someone. This place structure is captured by fi'o SELBRI fe'u, added to the main selbri, and then filled by lo skami. The idea of sumtcita is sometimes expressed in English using the following translation:

I translate this with-tool: A computer

A sumtcita can only absorb one sumti, which is always the following one. Alternatively, one can use the sumtcita construct by itself without sumti. In this case you need to put it either before the selbri or terminate it with ku. In such case one can think as if the sumtcita has the word zo'e as the sumti.

zukte = x1 is a volitional entity carrying out action x2 for purpose x3
zarci = x1 is a market/store/exchange/shop(s) selling/trading (for) x2, operated by/with participants x3

fi'o zukte {fe'u} ku lo prenu {ku} cu klama lo zarci {ku}{vau} - By their own volition, a person is going to the store

Note that there is ku in fi'o zukte {fe'u} ku. Without it the sumtcita would have absorbed lo prenu {ku} and we don't want that.

We can say the same in other words:

fi'o zukte {fe'u} zo'e lo prenu {ku} cu klama lo zarci {ku}{vau}

lo prenu {ku} cu fi'o zukte fe'u klama lo zarci {ku}{vau}

retaining the meaning.

What does mi jimpe fi lo skami fi'o se tavla {fe'u} mi state?

Putting the sumtcita right in front of the selbri also makes it self-terminate, since sumtcita only can absorb sumti, and not selbri. This fact will be of importance in next lesson, as you will see.

Actually, fi'o is not used very often despite its flexibility. What IS used very often, though, are BAI. BAI is a class of Lojban words, which in themselves act as sumtcita. An example of this is zu'e, the BAI for zukte. Grammatically, zu'e is the same as fi'o zukte fe'u. Thus, the above example could be reduced to:

zu'e ku lo prenu {ku} cu klama lo zarci {ku}{vau}. There exist something like 60 BAI, and a lot of these are very useful indeed. Furtermore, BAI can also be converted with se and friends, meaning that se zu'e is equal to fi'o se zukte fe'u, which results in a great deal more BAI.

## Lesson 10: PU, FAhA, ZI, VA, ZEhA, VEhA

How unfamiliar a language like Lojban must seem to an English-speaker, when one can read through nine lessons of Lojban grammar without meeting a tense once! This is because, unlike many natural languages (most Indo-European ones, for instance), all tenses in Lojban are optional. Saying mi citka lo cirla {ku} can mean I eat cheese or I ate the cheese or I always eat cheese or In a moment, i will have just finished eating cheese. Context resolves what is correct, and in most conversation, tenses are not needed at all. However, when it's needed it's needed, and it must be taught. Furthermore, Lojban tenses are unusual because they treat time and space fundamentally the same - saying that I worked a long time ago is not grammatically different than saying I work far away to the north.

Like many other languages, the Lojban tense system is perhaps the most difficult part of the language. Unlike many other languages though, it's perfectly regular and makes sense. So fear not, for it will not involve sweating to learn how to modify the selbri or anything silly like that.

No, in the Lojban tense system, all tenses are sumtcita, which we have conveniently just made ourselves familiar with. Okay okay, technically, tenses are slightly different from other sumtcita, but this difference is almost insignificant, and won't be explained until later. In most aspects they are like all other sumtcita; they are terminated by ku, making it explicit that PU is terminated by ku.

There are many different kinds of tense-sumtcita, so let's start at the ones most familiar to English-speakers.

pu = sumtcita: before {sumti}
ca = sumtcita: at the same time as {sumti}
ba = sumtcita: after {sumti}

These are like the English concepts before, now and after. In actuality though, one could argue that two point-like events can never occur exactly simultaneously, rendering ca useless. But ca extends slightly into the past and the future, meaning just about now. This is because human beings don't perceive time in a perfectly logical way, and the Lojban tense system reflects that.

Side note: It was actually suggested making the Lojban tense system relativistic. That idea, however, was dropped, because it is counter-intuitive, and would mean that to learn Lojban, one would have to learn the theory of relativity first.

So, how would you say I express this (pointing to a paper) after I came to this place?

Answer: mi cusku ti ba lo nu mi klama ti {vau} {kei} {ku} {vau}

Usually when speaking, we do not need to specify which event in the past this action is relative to. In: I gave a computer away, we can assume that the action happened relative to now, and thus we can elide the sumti of the sumtcita, because it's obvious:

pu ku mi dunda lo skami {ku} {vau} or

mi dunda lo skami {ku} pu {ku} {vau} or, more commonly

mi pu {ku} dunda lo skami {ku} {vau}. The sumti which fills the sumtcita is an implied zo'e, which is almost always understood as relative to the speaker's time and place (this is especially important when speaking about left and right). If speaking about some events that happened some other time than the present, it is sometimes assumed that all tenses are relative to that event which is being spoken about. In order to clarify that all tenses are relative to the speaker's current position, the word nau can be used at any time. Another word, ki marks a tense which is then considered the new standard. That will be taught way later.

nau = updates temporal and spacial frame of reference to the speaker's current here and now.
gugde = x1 is the country of people x2 with land/territory x3

Also note that mi pu {ku} klama lo merko gugde {ku} {vau}, I went to America, does not imply that I'm not still traveling to USA, only that it was also true some time in the past, for instance five minutes ago.

As mentioned, spacial and temporal time tenses are very much alike. Contrast the previous three time tenses with these four spacial tenses:

zu'a = sumtcita: left of {sumti}
ca'u = sumtcita: in front of {sumti}
ri'u = sumtcita: right of {sumti}
bu'u = sumtcita: at the same place as {sumti} (spacial equivalent of ca)
.o'o = attitudinal: complex pure emotion: patience - tolerance - anger

What would .o'o nai ri'u ku lo prenu {ku} cu darxi lo gerku {ku} pu {ku} {vau} mean?

darxi = x1 beats/hits x2 with instrument x3 at locus x4

Answer: {anger!} To the right (of something, probably me) and in the past (of some event), something is an event of a person beating a dog. or A man hit a dog to my right!

If there are several tense sumtcita in one bridi, the rule is that you read them from left to right, thinking it as a so called imaginary journey, Where you begin at an implied point in time and space (default: the speaker's now and here), and then follow the sumtcita one at a time from left to right.

Example

mi pu {ku} ba {ku} jimpe fi lo lojbo famyma'o {ku} {vau} = At some time in the past, I will be about to know about famyma'os.

mi ba {ku} pu {ku} jimpe fi lo lojbo famyma'o {ku} {vau} At some point in the future, I will have understood about famyma'os.

Since we do not specify the amount of time we move back or forth, the understanding could in both cases happen in the future or the past of the point of reference.

Also, if spacial and temporal tenses are mixed, the rule is to always put temporal before spacial.

Suppose we want to specify that the a man hit a dog just a minute ago. The words zi, za and zu specifies a short, unspecified (presumably medium) and long distance in time. Notice the vowel order i, a and u. This order appears again and again in Lojban, and might be worth to memorize. Short and long in are always context dependent, relative and subjective. Two hundred years is a short time for a species to evolve, but a long time to wait for the bus.

zi = sumtcita: Ocurring the small distance of {sumti} in time from point of reference
za = sumtcita: Ocurring the unspecified(medium) distance of {sumti} in time from point of reference
zu = sumtcita: Ocurring the far distance of {sumti} in time from the point of reference

Similarly, spacial distance is marked by vi, va and vu for short, unspecified (medium) and long distance in space.

vi = sumtcita: Ocurring the small distance of {sumti} in space from point of reference
va = sumtcita: Ocurring the unspecified(medium) distance of {sumti} in space from point of reference
vu = sumtcita: Ocurring the far distance of {sumti} in space from the point of reference
gunka = x1 works at x2 with objective x3

Translate: ba {ku} za ku mi vu {ku} gunka {vau}

Answer: Some time in the future, I will work a place far away

Note: People rarely use zi, za or zu without a pu or ba in front of it. This is because most people always need to specify past or future in their native language. When you think about it Lojbanically, most of the time the time-direction is obvious, and the pu or ba superfluous!

The order in which direction-sumtcita and distance-sumtcita are said makes a difference. Remember that the meanings of several tense words placed together are pictured by an imaginary journey reading from left to right. Thus pu zu is a long time ago while zu pu is in the past of some point in time which is a long time toward the future or the past of now. In the first example, pu shows that we begin in the past, zu then that it is a long time backwards. In the second example, zu shows that we begin at some point far away in time from now, pu then, that we move backwards from that point. Thus pu zu is always in the past. zu pu could be in the future. The fact that these time tenses combine in this way is one of the differences between tense sumtcita and other sumtcita. The meanings of other sumtcita are not altered by the presence of additional sumtcita in a bridi.

As briefly implied earlier, all these constructs basically treat bridi as if they were point-like in time and space. In actuality, most events play out over a span of time and space. In the following few paragraphs, we will learn how to specify intervals of time and space.

ze'i = sumtcita: spanning over the short time of {sumti}
ze'a = sumtcita: spanning over the unspecified (medium) time of {sumti}
ze'u = sumtcita: spanning over the long time of {sumti}
ve'i = sumtcita: spanning over the short space of {sumti}
ve'a = sumtcita: spanning over the unspecified (medium) space of {sumti}
ve'u = sumtcita: spanning over the long space of {sumti}

Six words at a time, I know, but remembering the vowel sequence and the similarity of the initial letter z for temporal tenses and v for spacial tenses might help the memorizing.

.oi = attitudinal: pain - pleasure

Translate: .oi dai do ve'u {ku} klama lo dotco gugde {ku} ze'u {ku} {vau}

Answer: Ouch, you spend a long time traveling a long space to Germany

ze'u and its brothers also combine with other tenses to form compound tenses. The rule for ze'u and the others are that any tenses preceding it marks an endpoint of the process (relative to the point of reference) and any tenses coming after it marks the other endpoint relative to the first. This should be demonstrated with a couple of examples:

.o'ocu'i do citka pu {ku} ze'u {ku} ba {ku} zu {ku} {vau} - {tolerance} you eat beginning in the past and for a long time ending at some point far into the future of when you started or Hmpf, you ate for a long time. One can also contrast do ca {ku} ze'i {ku} pu {ku} klama {vau} with do pu {ku} ze'i {ku} ca {ku} klama {vau}. The first event of traveling has one endpoint in the present and extends a little towards the past, while the second event has one endpoint in the past and extends only to the present (that is, slighty into the past or future) of that endpoint.

jmive = x1 is alive by standard x2

What does ui mi pu {ku} zi {ku} ze'u {ku} jmive {vau} express?

Answer: {happiness!} I live from a little into the past and a long way towards the future or past (obviously the future, in this case) of that event or I am young, and have most of my life ahead of me :)

Just to underline the similarity with spacial tenses, let's have another example, this time with spacial tenses:

.u'e = attitudinal: wonder - commonplace

.u'e za'a bu'u {ku} ve'u {ku} ca'u {ku} zdani {vau} - What does it mean?

Answer: {wonder} {I observe!} Extending a long space from here to my front is a home. or Wow, this home extending ahead is huge!

Before we continue with this syntax-heavy tense system, i recommend spending at least ten minutes doing something which doesn't occupy your brain in order to let the information sink in. Sing a song or eat a cookie very slowly - whatever, as long as you let your mind rest.

## Lesson 11: ZAhO

Though we won't go through all Lojban tense constructs for now, there is one other kind of tense that I think should be taught now. These are called event contours, and represent a very different way of viewing tenses that we have seen so far. So let's get to it:

Using the tenses we have learned so far, we can imagine an indefinite time line, and we then place events on that line relative to the now. With event contours, however, we view each event as a process, which has certain stages: A time before it unfolds, a time when it begins, a time when it is in process, a time when it ends, and a time after it has ended. Event contours then tells us which part of the event's process was happening during the time specified by the other tenses. We need a couple of tenses first:

pu'o = sumtcita: event contour: Bridi has not yet happened during {sumti}
ca'o = sumtcita: event contour: Bridi is in process during {sumti}
ba'o = sumtcita: event contour: The process of bridi has ended during {sumti}

This needs to be demonstrated by some examples. What's ui mi pu'o {ku} se zdani {vau} mean?

But hey, you ask, why not just say ui mi ba {ku} se zdani {vau} and even save a syllable? Because, remember, saying that you will have a home in the future says nothing about whether you have a home now. Using pu'o, though, you say that you are now in the past of the process of you having a home, which means that you don't have one now.

Note, by the way, that mi ba {ku} se zdani {vau} is similar to mi pu'o {ku} se zdani {vau}, and likewise with ba'o and pu. Why do they seem reversed? Because event contours view the present as seen from the viewpoint of the process, whereas the other tenses view events seen from the present.

Often, event contours are more precise that other kind of tenses. Even more clarity is achieved by combining several tenses: .a'o mi ba {ku} zi {ku} ba'o {ku} gunka {vau} - I hope I've soon finished working.

In Lojban, we also operate with an event's natural beginning and its natural end. The term natural is highly subjective in this sense, and the natural end refers to the point in the process where it should end. You can say about a late train, for instance, that its process of reaching you is now extending beyond its natural end. An undercooked, but served meal, similarly, is being eaten before that process' natural beginning. The event contours used in these examples are as follows:

za'o = sumtcita: event contour: Bridi is in process beyond its natural end during {sumti}
xa'o = sumtcita: event contour: Bridi is immaturely in process during {sumti}
cidja = x1 is food, which is edible for x2

Translate: .oi do citka za'o lo nu do ba'o {ku} u'e citka zo'e noi cidja do {vau} {ku'o} {vau} {kei} {ku}

Answer: Oy, you keep eating when you have finished, incredibly, eating something edible!

Image above: ZAhO tenses (event contours). All tenses above the line of the event signify stages covering an amount of time. All tenses below the event line signify stages which are point-like.

All of these tenses have been describing stages of a process which takes some time (as shown on the graph above; those tenses above the event like). But many of the event contours describes point like stages in the process, like its beginning. As is true of ca and bu'u, they actually extend slightly into the past and future of that point, and need not to be precise.

The two most important point-like event contours are:

co'a = sumtcita: event contour: Bridi is at its beginning during {sumti}
co'u = sumtcita: event contour: Bridi is at its ending during {sumti}

Furthermore, there is a point where the process is naturally complete, but not necessarily has ended yet:

mo'u = sumtcita: event contour: Bridi is at its natural ending during {sumti}

Most of the time, though, processes actually end at their natural ending; this is what makes it natural. Trains are not usually late, and people usually retrain themselves to eat only edible food.

Since a process can be interrupted and resumed, these points have earned their own event contour also:

de'a = sumtcita: event contour: Bridi is pausing during {sumti}
di'a = sumtcita: event contour: Bridi is resuming during {sumti}

In fact, since jundi means x1 pays attention to x2, de'a jundi and di'a jundi are common Lojban ways of saying BRB and back. One could of course also say the event contours by themselves and hope the point gets across.

Finally, one can treat an entire event, from the beginning to the end as one single point using co'i:

penmi = x1 meets x2 at location x3

mi pu {ku} zi {ku} co'i {ku} penmi lo dotco prenu {ku} {vau} - A little while ago, I was at the point in time where i met a German person