internal grammar of tags

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Tense grammar simplification proposal, by la xorxes.

Current grammar

tense-modal = simple-tense-modal # | FIhO # selbri /FEhU#/ 

simple-tense-modal = [NAhE] [SE] BAI [NAI] [KI] 
| [NAhE] (time [space] | space [time]) & CAhA [KI] 
| KI 
| CUhE

time = ZI & time-offset ... & ZEhA [[PU [[NAI]] & interval-property ...

time-offset = PU [NAI] [ZI]

space = VA & space-offset ... & space-interval & (MOhI space-offset)

space-offset = FAhA [NAI] [VA]

space-interval = ((VEhA & VIhA) [[FAhA [[NAI]]) & space-int-props

space-int-props = (FEhE interval-property) ...

interval-property = number ROI [NAI] | TAhE [NAI] | ZAhO [NAI]

Proposed grammar

tense-modal = ([NAhE] [SE] tag-unit [NAI] #) ... 

tag-unit = BAI 
| CAhA 
| CUhE 
| KI 
| ZI 
| PU 
| VA 
| [MOhI] FAhA 
| ZEhA 
| VEhA 
| VIhA 
| [FEhE] number ROI 
| [FEhE] TAhE 
| [FEhE] ZAhO 
| FIhO # selbri /FEhU/



Every tag-unit can be used as a tag, and therefore as a connective. It is arbitrary and inconvenient that SE is currently disallowed with some tags.


NAhE PU, NAhE CAhA and NAhE PU CAhA are all allowed, but NAhE PU NAhE CAhA is not. This is arbitrary and inconvenient. Similarly for other combinations.

Order of units

co'a na'o broda (starting to typically broda) is allowed, but na'o co'a broda (typically starting to broda) is not. It will be accepted by the parser, but parsed as na'oku co'a broda. Similarly for all other order restrictions. Note: arbitrary combinations of tag-units are already allowed in selbri-tags as long as there is an intervening ja'a, for example: na'o ja'a co'a broda is allowed, without kus.


There's no good reason to allow it selectively here and there instead of everywhere.

Backwards compatibility

Fully compatible. Everything currently grammatical remains grammatical.


  1. In the original proposal I had kept PU [ZI], FAhA [VA], ZEhA [PU], VEhA [FAhA] and VIhA [FAhA] as separate forms because I thought their compound meaning might follow special compositional rules. I don't think that is the case, though. Just as the Imaginary Journey composition follows the ordinary left-to-right scope rule, these compounds follow the rule too. For example, ze'u pu indicates a long duration of an event in the past of some reference point, where the event is in the past for the whole duration.
  2. Originally I had only redefined the simple-tense-modal, but since the exclusion of FIhO-modals from the general case was due to the LR(1) restriction which no longer applies, we can now generalize the full tense-modal.


  • la fagri
    • Are you sure PU [ZI] and the others don't follow special rules? Under CLL, {pu zu broda} means "A long time in the past, broda occurs" but if you try to separate it out into a two-step imaginary journey, you get "In the past of a long time away from now, broda occurs". If you take your "long time away" walk in the future-ward direction, then from that vantage point, {pu} encompasses the present and the near future.
  • And Rosta:
    • SE: Absolutely, yes.
    • NAhE: Yes.
    • Order: Is lo na'o(ku) co'a broda grammatical? If not, then that is an argument in favor of your proposal. If it is grammatical, then I think it would be better if all selbri tags were instead sumti tags, since otherwise we have a syntactic distinction with no semantic import.
      • lo na'oku co'a broda is not grammatical. lo na'o ja'a co'a broda is grammatical. But having to remember for which combinations you need to insert ja'a is absurd.
        • OK, then. I am in favour.
    • NAI: Certainly the status quo seems arbitrary. But IMO NAI is a Bad Thing when it contributes to logical form, because it doesn't follow the usual scope rules. Allowing NAI everywhere is probably better than allowing it arbitrarily, but better would be to disallow it everywhere except for places where na can't do the job.
      • NAI only affects the meaning of the previous word. For example ru'inai means "intermittently". It follows the usual scope rule for UIs, the scope is always the previous word. If you prefer, the complex word+nai is a new word with a new meaning. The new meaning is not strictly compositional, but it is usually easy to guess.
        • So it functions like NAhE, then? I agree the status quo is an ugly mess, but the risk of fixing it by allowing NAI anywhere is that we end up with a semantic mess. Are we (BF) really going to say for every cmavo what it means when followed by NAI? Or is it like a tanru, dependent on glorking?
          • I will restrict it, for the purposes of this proposal, to words in tags. NAI is already allowed after most of them anyway, so we already have to do that.