10.23. Tenses versus modals

Grammatically, every use of tenses seen so far is exactly paralleled by some use of modals as explained in Chapter 9. Modals and tenses alike can be followed by sumti, can appear before the selbri, can be used in pure and mixed connections, can participate in JAI conversions. The parallelism is perfect. However, there is a deep difference in the semantics of tense constructs and modal constructs, grounded in historical differences between the two forms. Originally, modals and tenses were utterly different things in earlier versions of Loglan; only in Lojban have they become grammatically interchangeable. And even now, differences in semantics continue to be maintained.

The core distinction is that whereas the modal bridi

Example 10.171.

mi	nelci	do	mu'i	le	nu	do	nelci	mi
I	like	you	with-motivation	the	event-of	you	like	me.

I like you because you like me.

places the le nu sumti in the x1 place of the gismu mukti (which underlies the modal mu'i), namely the motivating event, the tensed bridi

Example 10.172.

mi	nelci	do	ba	le	nu	do	nelci	mi
I	like	you	after	the	event-of	you	like	me.

I like you after you like me.

places the le nu sumti in the x2 place of the gismu balvi (which underlies the tense ba), namely the point of reference for the future tense. Paraphrases of Example 10.171 and Example 10.172, employing the brivla mukti and balvi explicitly, would be:

Example 10.173.

le	nu	do	nelci	mi	cu	mukti	le	nu
The	event-of	you	like	me		motivates	the	event-of

mi	nelci	do
I	like	you.

Your liking me is the motive for my liking you.

and

Example 10.174.

le	nu	mi	nelci	do	cu	balvi	le	nu
The	event-of	I	like	you		is-after	the	event-of

do	nelci	mi
you	like	me.

My liking you follows (in time) your liking me.

(Note that the paraphrase is not perfect due to the difference in what is claimed; Example 10.173 and Example 10.174 claim only the causal and temporal relationships between the events, not the existence of the events themselves.)

As a result, the afterthought sentence-connective forms of Example 10.171 and Example 10.172 are, respectively:

Example 10.175.

mi	nelci	do	.imu'ibo	do	nelci	mi
I	like	you.	[That-is] Because	you	like	me.

Example 10.176.

do	nelci	mi	.ibabo	mi	nelci	do
You	like	me.	Afterward,	I	like	you.

In Example 10.175, the order of the two bridi mi nelci do and do nelci mi is the same as in Example 10.171. In Example 10.176, however, the order is reversed: the origin point do nelci mi physically appears before the future-time event mi nelci do. In both cases, the bridi characterizing the event in the x2 place appears before the bridi characterizing the event in the x1 place of mukti or balvi.

In forethought connections, however, the asymmetry between modals and tenses is not found. The forethought equivalents of Example 10.175 and Example 10.176 are

Example 10.177.

mu'igi	do	nelci	mi	gi	mi	nelci	do
Because	you	like	me	,	I	like	you.

and

Example 10.178.

bagi	do	nelci	mi	gi	mi	nelci	do
After	you	like	me	,	I	like	you.

respectively.

The following modal sentence schemata (where X and Y represent sentences) all have the same meaning:

X .i BAI bo Y

BAI gi Y gi X

X BAI le nu Y

whereas the following tensed sentence schemata also have the same meaning:

X .i TENSE bo Y

TENSE gi X gi Y

Y TENSE le nu X

neglecting the question of what is claimed. In the modal sentence schemata, the modal tag is always followed by Y, the sentence representing the event in the x1 place of the gismu that underlies the BAI. In the tensed sentences, no such simple rule exists.