Chapter 9. Time & Space#

Tense Is Optional#

Lojban bridi carry no mandatory tense. The sentence mi klama le zarci can mean "I went", "I go", "I will go", or "I habitually go" — context decides which. This is deliberate: you only add tense information when it matters to the conversation.

When you do want to specify time, place a tense particle immediately before the selbri (or right after cu):

mi pu klama le zarci I [past] go to the store. → I went to the store.

mi ca klama le zarci I [now] go to the store. → I am going to the store.

mi ba klama le zarci I [future] go to the store. → I will go to the store.

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The Three Time Directions: pu, ca, ba#

pu

(particle) before now / in the past

ca

(particle) at the same time / now / present

ba

(particle) after now / in the future

These three are the heart of Lojban's tense system. They come from the gismu purci (past), cabna (present), and balvi (future).

la .teris. pu klama le barda tcadu Terry went to the big city.

la .teris. ba sipna Terry will sleep.

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Time Distances: zi, za, zu#

Add a ZI particle after the direction to say how far in the past or future:

zi

short time distance (moments ago / soon)

za

medium time distance (hours, days, a while)

zu

long time distance (years, ages)

Combine direction + distance:

mi puzi citka I ate a short time ago. (recently)

mi puzu citka I ate a long time ago.

mi bazi klama I'll go very soon.

mi bazu klama I'll go a long time from now.

The distance words alone, without a direction, indicate "near/far in time but unspecified direction":

mi zi klama I go/went/will go close to now. (around now, not exactly now)

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Time Intervals: ze'i, ze'a, ze'u#

The ZEhA particles describe how long the event lasts, rather than when it happens:

ze'i

short time interval (briefly)

ze'a

medium time interval (for a while)

ze'u

long time interval (for a long time)

mi ze'u sipna I sleep for a long time.

le verba pu ze'a cadzu le bisli The child walked on the ice for a while.

Interval words come after direction words:

mi pu ze'a citka I was eating for a while [in the past].

You can also specify where in the interval the reference point falls by adding another direction after the interval:

mi ca ze'ica cusku dei I am [now, short-interval spanning now] saying this. → I am now saying this sentence.

mi ca ze'ipu cusku dei I have just been saying this. (interval extends into the past from now)

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Tense Scope: ku#

Normally a tense particle before the selbri applies to that bridi. To move it elsewhere for emphasis, add ku after it:

puku mi klama le zarci Earlier, I went to the store. (pu emphasized at the front)

mi klama le zarci puku I went to the store [earlier]. (pu at the end)

ku after a tense is an elidable terminator. At the end of a bridi it can usually be dropped.

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Space Tenses: vi, va, vu and FAhA#

Lojban has spatial tenses too, working exactly like temporal ones. Think of them as an imaginary journey from the speaker to where the event happens.

Distance (VA):

vi

short distance / here

va

medium distance / nearby

vu

long distance / over there / far away

vi, va, vu work as spatial sumti tcita: they take a location landmark as their argument, just as pu/ca/ba take a time argument.

le ratcu cu citka le cirla vi le panka The rat eats the cheese near the park.

le ratcu cu citka le cirla vu le vi panka The rat eats the cheese far from the nearby park.

Direction (FAhA): specifies which way to travel

Direction before distance:

le nanmu zu'a batci le gerku To my left, the man bites the dog.

le nanmu zu'avi batci le gerku A short distance to my left, the man bites the dog.

Compound spatial tenses chain journeys:

le nanmu ga'u zu'a batci le gerku Left of a place above me, the man bites the dog. (go up, then go left)

Space intervals (VEhA):

ve'i

small space interval

ve'a

medium space interval

ve'u

large space interval

le verba ve'i cadzu le bisli The child walks on the ice in a small area.

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Combining Time and Space#

When both time and space tenses appear in one bridi, time comes first:

le nanmu puzu vu batci le gerku Long ago and far away, the man bit the dog.

mi bazi vi klama I'll go here soon.

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Aspect: co'a, co'i, ca'o, co'u#

Aspect describes the shape of an event — is it beginning, in-progress, or complete? Aspect particles also go before the selbri (or after a tense particle):

co'a

begins / starts (inchoative)

ca'o

continues / is ongoing

co'u

ends / stops

co'i

completes / perfective

mo'u

reaches endpoint / finishes

za'o

continues past its natural endpoint (excessive)

la .teris. co'a cadzu Terry starts walking.

mi ca'o citka I am (continuously) eating.

le nu klama cu co'i The going is/has completed.

mi co'u tavla I stopped talking.

From the Terry story:

la .teris. co'a cadzu klama le bi'unai barda tcadu Terry started walking to the big city.

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Tense in Subordinate Clauses#

Tenses in embedded clauses are relative to the event time of the main clause, not the speaker's present:

mi pu djuno le du'u do ba klama I knew [past] that you would go [future relative to that past time].

This parallels how English uses "would" in reported speech. The tense system is consistent and compositional.

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Motion Tenses: mo'i + FAhA#

The particle mo'i marks that the event involves motion in a direction, rather than just location. Combine it with a FAhA direction particle:

mi mo'i ca'u cadzu I walk [moving forward]. (the walking involves forward movement)

le gerku mo'i ri'u bajra The dog runs to the right.

le vinji mo'i ga'u klama The airplane comes [moving upward]. (taking off)

Without mo'i, a direction particle just says where the event is:

le nanmu ca'u batci le gerku = The man bites the dog in front of me. (location) le nanmu mo'i ca'u batci le gerku = The man, moving forward, bites the dog. (motion)

mo'i can combine with time and distance tenses as usual:

mi pu mo'i fa'a le zarci klama I went [past] moving toward the store. (I headed toward the store)

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Interval Boundaries: ga'o and ke'i#

When you specify a time or space interval, you can mark whether the endpoints are included or excluded — like closed vs. open intervals in mathematics:

These appear right before or after interval words to mark which end they apply to:

mi cadzu ga'o le zarci ke'i le briju I walk from the store (inclusive) to the office (exclusive). = I leave from the store (starting point counts) and stop just before the office.

mi sipna ze'u ga'o le nu co'a nicte ke'i le nu co'a donri I sleep from when night begins (inclusive) to when day begins (exclusive).

In practice, the closed/open distinction is mostly relevant in precise mathematical or scheduling contexts, but it mirrors standard mathematical notation and is grammatically available for all interval expressions.

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Rhythm and Habit: TAhE#

The TAhE particles express whether an event happens regularly, continuously, habitually, or at some other rhythmic pattern:

mi ta'e citka lo plise I habitually eat apples. (it's my habit)

le mlatu na'o sipna Cats typically sleep. (it's normal for cats)

le pulce ru'i cpana le rokci The dust continuously lies on the rock.

mi di'i viska le solri I regularly see the sun. (at predictable intervals — every morning)

TAhE particles can combine with time tenses:

mi pu ta'e citka lo plise I used to habitually eat apples. (past habit)

mi ba di'i klama le zarci I will regularly go to the store.

The difference between ta'e and di'i:

• ta'e = habitually (general tendency, not necessarily at fixed intervals)
• di'i = periodically (at predictable, regular intervals — like every Tuesday)

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Quick Reference#

Temporal directions:

Aspect:

Space distances: vi (near), va (medium), vu (far)

Space intervals: ve'i (small area), ve'a (medium), ve'u (large)

Time intervals: ze'i (briefly), ze'a (a while), ze'u (long time)

Motion: mo'i + FAhA direction = moving-in-that-direction

Interval boundaries: ga'o (closed/inclusive), ke'i (open/exclusive)

Rhythm/habit (TAhE): ta'e (habitual), na'o (typical), ru'i (continuous), di'i (periodic)

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CAhA: Actuality, Potentiality, and Capability#

CLL chapter 10 covers a selma'o called CAhA that lets you distinguish not just when something happens but whether it could happen at all:

le karce ca'a klama le zarci The car actually goes to the store. (it's a fact right now)

le karce ka'e klama le zarci The car is capable of going to the store. (in principle — whether or not it does)

mi nu'o vofli I can fly but never have. (untried — I have the theoretical ability but no evidence)

mi pu'i vofli I have actually flown. (demonstrated capability — the proof is in the past event)

ca'a vs. bare tenses: a bare bridi without tense is tenseless (true at some time); ca'a asserts the present fact explicitly. In logical argument, ca'a is the "actualization" operator.

ka'e is especially useful for capabilities of artifacts, animals, and people:

le gerku ka'e batci A dog is able to bite. (it's within their nature)

le verba nu'o cadzu The child can walk but hasn't yet.

Note on universal statements: Lojban tenseless bridi describe what is universally true of a kind, not what is happening now. So ro datka cu flulimna ("all ducks float-swim") is considered true even of sleeping ducks, because it describes their nature. Adding a tense marker — ro datka ca flulimna — still doesn't fully assert current activity; it only narrows the time. For an unambiguous "all ducks are right now actually swimming" you need ca'a: ro datka ca ca'a flulimna.

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VIhA: Dimensionality of Events#

Events can be point-like, linear, areal, or volumetric. The VIhA particles tag this:

mi vi'i klama le bisli I travel along the ice in a line. (linear path)

le bredi cu vi'a cpana le foldi The seed covers the field (as a surface).

le djacu cu vi'u nenri le botpi The water fills the bottle (volumetrically).

VIhA is used mainly in precise spatial descriptions; for everyday speech the bare VA distance particles are usually enough.

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Story Time: Tenses Relative to Narrative Point#

In narrating events, you often set a story-time reference point and then describe other events relative to it. Lojban handles this explicitly with ki:

ki — "sticky tense" bookmark

Attaches to a tense to make it the persistent reference point for subsequent bridi.

puki mi klama le zarci .i le zarci cu barda [Setting: past.] I go to the store. The store is big. (both past)

With ki appended to a tense particle, all subsequent bridi without an explicit tense use that reference:

puki = set "past" as the current reference point baki = set "future" as the reference caki = reset to "present" (speaker's now)

This is how Lojban fiction works: set puki once, and everything that follows is understood as past until reset:

puki la .teris. klama le tcadu .i ri melbi .i la .teris. facki lo cukta [Past:] Terry goes to the city. It is beautiful. Terry finds a book.

All three sentences are past without repeating pu each time.

Without ki, every bridi resets to tenseless (ambiguous time). With ki, you establish a narrative time and stay there.

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Compound Spatial Tenses#

Spatial tense particles can be chained to describe a multi-step imaginary journey through space. Each step adds a direction (FAhA) optionally followed by a distance (VA):

le nanmu ga'u zu'a batci le gerku The man [up] [left] bites the dog. To the left of a place above me, the man bites the dog.

The journey proceeds left to right: first move upward from the speaker, then move left from there. The English gloss reverses the order (innermost step first).

You can attach a distance to each direction separately:

le nanmu zu'avi ga'u vu batci le gerku The man [left-short] [up-long] bites the dog. Far above a place slightly to my left, the man bites the dog.

A distance without a following direction says how far away the event is without specifying direction:

le nanmu vi zu'a batci le gerku The man [short-distance] [left] bites the dog. Left of a place near me, the man bites the dog.

Any number of direction+distance steps may be stacked. In practice, one or two steps are most common.

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Interval Sizes: VEhA and ZEhA#

By default, a tense just says when something happens — it says nothing about how long it takes. The cmavo of VEhA (space) and ZEhA (time) specify the size of the interval over which the event occurs.

These are relative to context — "short" for a geological event is different from "short" for a sentence.

le verba ze'a cadzu le bisli The child [medium-time-interval] walks on the ice. For a medium amount of time, the child walks on the ice.

ZEhA as a sumti tcita (interval specified by reference to an event):

loi snime cu carvi ca le ze'u dunra Snow falls during the long winter. (the winter is long; the snow falls in it)

Here le ze'u dunra is the sumti of the tense tag ca — the event of snow falling is located within the interval described as "the long winter."

le verba ve'i cadzu le bisli The child [small-space-interval] walks on the ice. The child walks on the ice in a small area.

Intervals combine with directions and distances. The interval always comes after the distance/direction:

le verba pu ze'a cadzu le bisli The child [past] [medium-interval] walks on the ice. For a medium time in the past, the child walked on the ice.

Orienting the interval#

By adding a PU or FAhA cmavo after the ZEhA (or VEhA), you specify where the reference point falls relative to the interval:

mi ca ze'ica cusku dei I [present] [short-interval-present] say this. I am saying this sentence now. (the interval straddles the present moment)

mi ca ze'ipu cusku dei I [present] [short-interval-past] say this. I have just been saying this sentence. (interval extends from the past to now)

mi pu ze'aba citka le mi sanmi I [past] [medium-interval-future] eat my meal. For a medium time afterward [from that past moment], I ate my meal.

Without the trailing PU/FAhA, the relationship between reference point and interval is unspecified.

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Space Interval Modifier: FEhE#

The ZAhO aspect particles (co'a, ca'o, co'u, mo'u, za'o) normally describe the phase of an event in time. The cmavo fe'e (selma'o FEhE) is a flag that transfers the ZAhO interpretation to space — meaning "apply this event-contour notion to space, not time."

ko vi'i fe'e di'i sombo le gurni You [1-dimensional] [space:] [regularly] sow the grain. Sow the grain evenly in a line!

mi fe'e ciroi tervecnu lo selsalta I [space: three-places] buy salad ingredients. I buy salad ingredients at three separate locations.

The fe'e prefix can also be used with ZAhO:

tu ve'abe'a fe'e co'a rokci That [medium-space-interval-north] [space:] [start-of] is-a-rock. That is the beginning-edge of a rock extending northward from me.

Here co'a (beginning of) is applied to the spatial extent of the rock rather than to time — the southern face is the "beginning" because the interval extends northward.

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Story Time#

In ordinary Lojban, a tenseless bridi has no implied temporal relationship to other bridi. But in narrative — a story, a report, a sequence of events — speakers use a different convention called story time.

In story time:

• Each new tenseless sentence is understood to occur after the previous one.
• A sticky tense set with ki establishes the narrative starting point.
• An explicit tense in a sentence is interpreted relative to the current story time, not the speaker's present.
• After a flashback (a sentence with explicit tense reaching back in time), story time returns to where it was before the flashback.

Example mini-story:

pu zu ki ku — [long ago, sticky:]

This sets the story to "long ago." From here, all tenseless sentences are understood as long ago, advancing forward in time.

.i ko'a citka loi kanba rectu — She was eating goat's meat. .i ko'a pu jukpa ri le mudyfagri — (Flashback) She had cooked it over a wood fire. .i lei rectu cu zanglare — The meat was pleasantly warm. (story time resumes after the flashback)

The flashback with pu goes before the eating event but does not advance story time. After the flashback sentence, story time picks up where the eating left off.

Story time is how Lojban narratives are written naturally — set a time with ki, then let sentences flow without repeating the tense. Use explicit tenses only for flashbacks (pu) or flash-forwards (ba).

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Tenses in Subordinate Bridi#

When a bridi is embedded inside another (as an abstraction, relative clause, or description), the inner tense is interpreted relative to the outer tense, not relative to the speaker's present.

English works differently: English always measures tense from the speaker's present. Lojban follows the convention of Russian and Esperanto — relative tense.

la djan. ca cusku le se du'u la jord. ca klama le zarci John [present] says the-statement-that George [present] goes to the market. John says that George is (right now, while John speaks) going to the market.

la djan. pu cusku le se du'u la jord. ca klama le zarci John [past] said the-statement-that George [present] goes to the market. John said that George was (at the time of John's saying) going to the market.

In the second sentence, ca inside the subordinate bridi means "simultaneously with John's speaking (in the past)" — not "simultaneously with right now." This is the key difference from English.

la djan. pu cusku le se du'u la jord. pu klama le zarci John [past] said the-statement-that George [past] went to the market. John said that George had gone to the market (before the moment of speaking).

nau: Override to Speaker's Present#

When you are deep inside nested subordinate bridi but want to refer to the speaker's actual present moment (not the relativized one), use nau (selma'o CUhE):

la djan. pu cusku le se du'u nau mi sipna John [past] said the-statement-that [now-actually] I am asleep. John said that (as I am telling you this) I am asleep.

nau escapes all the relative tense nesting and points directly to the moment of utterance. It cannot be combined with other tense particles (except through logical connection). It has no effect on sticky tenses.

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Tense Negation#

Tense particles can be negated with nai to produce roughly the opposite meaning:

mi pu klama le zarci — I went to the store. mi punai klama le zarci — I didn't go to the store [in the past]. (equivalent to na in many contexts, but specifically negates the tense)

More usefully, nai on ZAhO aspect particles means the event is not at that stage:

mi ca'onai citka — I am not in the middle of eating.

Tense negation contrasts with bridi negation (na): mi na pu klama negates the whole claim (it is not the case that I went), while mi punai klama specifically says "at past time, not going" — a subtle but sometimes important distinction.

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Vague intervals — pu is not English “finished past”#

If you do not give a ZEhA interval size, Lojban leaves the interval vague. mi pu klama le zarci puts some part of the going in the speaker’s past — it does not promise the whole trip ended before “now” (English went often implies completion). Likewise:

le tricu ba crino The tree will be green — does not exclude the tree being green already; the stretch of “being green” may have begun.

To force completion, phases, or duration, use ZAhO (co'i, co'u, …), ze'a, or more specific wording — not pu alone.

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Tense tagging a sumti (sumti tcita)#

Besides floating tenses (ku) or pre-selbri position, a tense can sit immediately before a sumti to relate the main bridi to that sumti in time or space.

Time:

mi klama le zarci ca le nu do klama I go to the store at the same time as your going.

mi klama le zarci pu le nu do pu klama le zdani I go to the market in the past of your (then) going to the house — often glossed as *I had gone to the market before you went to the house._

Space:

le ratcu cu citka le cirla vi le panka The rat eats the cheese in the vicinity of the park.

jai + tense promotes the tagged place to x₁ of a new selbri; the old x₁ can reappear as fai (Chapter 4):

le panka cu jai vi citka le cirla fai le ratcu The park is the locus of the rat’s eating the cheese.

mi djuno fi le jai ca morsi be fai la .djan. I know about the time when John is dead — the time of John’s death.

Temporal ZAhO and roi can also tag sumti; see CLL-style advanced examples when you need phase-of-process relative to le nu.

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Sub-events: stacked contours and counts#

You can stack aspect and repetition without a connective:

la .djorj. ca'o co'a ciska George continues to begin to write. (each cmavo narrows the phase)

mi reroi ca'o xaroi darxi le damri On two occasions, I keep hitting the drum six times each time.

The cross-product connective pi'u between counts (CLL’s “twelve shots” from 2×6) exists but is rare; treat it as advanced.

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Tenses vs modals#

Syntax: Tenses and modals occupy the same structural “slots”: before the selbri, with ku, as sumti tcita, in connections, and with jai. Semantics: tenses answer when / where the bridi sits; modals add why / how / in what language / with what tool — roles beyond the gismu’s built-in places. A single bridi can carry both: mi pu klama le zarci mu'i le nu mi djica — past going, motivated by wanting.

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Beyond “short / medium / long” distances#

ZI and VA only give three coarse sizes. For exact offsets or durations, Lojban uses mekso (numbers), nu'i … nu'u termsets after a tense tag, and related machinery (Chapter 14, Chapter 16, Chapter 18). Everyday prose rarely needs this; skip until you write precise schedules or physics.

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Full FAhA direction inventory (reference)#

The quick table earlier lists common directions. The full set includes (static “where” / mo'i “moving” uses the same cmavo):

Compass and viewer-relative directions mix; pick one frame and stay consistent in a passage.

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Finally: mixed tense practice (capstone)#

Use this block to integrate everything from the chapter: read, name the pieces, produce.

1 — Identify components
For each bridi, say which selma’o you see (e.g. PU, ZI, ZEhA, FAhA, VA, ZAhO, ROI …) and in what order they attach:

mi puze'a klama le zarci

le verba cu vi ne'i le zdani co'u sipna

la .djan. reroi pu klama le briju

2 — Paraphrase
Express roughly: “I will go to the store soon” vs “I will go to the store a long time from now” using ba + ZI (and ku only if you need to front the tense).

3 — Connective question (ties to Chapter 8 and Chapter 16):

la .artr. pu je'i ba nolraitru

What does je'i ask for? What kinds of answer are grammatical?

4 — Optional stretch (harder)
Skip these until the rest of the chapter feels easy; they mix sticky tense, double aspect, and “vague future” readings.

• Sticky narrative: puki is pu + ki — the tense sticks for later bridi. What tense is the second sentence?

  mi puki klama le zarci .i mi klama le zdani I [past-sticky] went to the market. I go to the house.

• Stacked contours: Name both ZAhO pieces and the overall story (start vs stop vs ongoing):

  mi ca'o co'u bajra

• Vague interval (trap): Does ba always mean “will / going to”? Paraphrase the following without adding a false English “will”:

  le tricu ba crino

For bridi negation vs tense order (na ku), see Chapter 13.

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Summary#

• Tense is always optional; omit it when context is clear
• pu / ca / ba = past / present / future
• zi / za / zu = short / medium / long time distance (combined: puzi, bazu, etc.)
• ze'i / ze'a / ze'u = interval size (how long the event lasts)
• Spatial tenses use vi/va/vu (distance) and FAhA particles (direction)
• mo'i + FAhA = motion tense (the event involves movement in that direction)
• ga'o = closed endpoint (inclusive); ke'i = open endpoint (exclusive)
• TAhE rhythm: ta'e (habit), na'o (typical), ru'i (continuous), di'i (periodic)
• Time comes before space when both are given
• Aspect particles (co'a, ca'o, co'i, co'u, mo'u, za'o) describe the shape of events
• Use ku to move a tense out of default position for emphasis
• CAhA: ca'a (actually), ka'e (capable), nu'o (untried), pu'i (demonstrated)
• VIhA: vi'i (line), vi'a (surface), vi'u (volume), vi'e (space-time)
• ki: sticky-tense bookmark — sets reference for subsequent bridi; caki resets to present

Compound spatial tenses:

• Multiple FAhA cmavo stack (inner first): zu'avi'i = a short line forward
• VEhA (spatial interval): ve'i = small area, ve'a = medium, ve'u = large
• ZEhA (temporal interval): ze'i = short, ze'a = medium, ze'u = long
• Both stack on direction: puze'a = for a medium past duration

FEhE — space interval modifier:

• Placed after a spatial tense to specify the shape of the space interval
• vi FEhE + FAhA = the space around the event is in direction FAhA

Story time and nau:

• ki (sticky tense) advances the narrative reference time implicitly in stories
• Tenseless sentences in a narrative pick up the sticky tense from prior context
• nau overrides all tense context — forces interpretation relative to speaker's actual now
• puki = set story-past reference; subsequent sentences without tense are past relative to it

Finally (capstone): mixed tense drills + je'i — see Finally: mixed tense practice above (including optional stretch)