Consider a complex proposition ‘S↴ (subordinate ↴S)’, where subordinate is a subordinator coding some interpropositional relation. In such a construction, S↴ may be a human action. Linguistic operations, including speech acts and modal operations of the speaker on a proposition, are among such actions. For instance, such a linguistic operation of the speaker may be motivated by a reason or guided by a purpose or be contingent on a condition, as in E1 – E3.

In such cases, the subordinate proposition is not related to the proposition expressed by the main clause – e.g. in E1, his shoes' lying there is not a reason for his being back –, but to some linguistic operation performed by the speaker in uttering the sentence – for instance, to the inference expressed in E1.

There are, consequently, two pragmatic levels at which a subordinate proposition may be positioned:

1. at the level of the designatum,
2. at the level of the speech act, including its component propositional and illocutionary acts.
   This level may again be subdivided into:
   1. the epistemic level, at which the speaker executes modal operations on the proposition expressed in the main clause (as in E1),
   2. the illocutionary level, at which the speaker uses his utterance according to some relevant social convention (as in E3).

Alternative 2) is available only for some interpropositional relations which center around motivations and social conditions for cognitive and communicative acts. Thus, there are, for instance, no local and temporal propositions at the second level. Conversely, all of the interpropositional relations are possible at the level of the designatum, for the simple reason that whatever a speaker can do in speaking may also be designated by a sentence.

The onomasiological description brings out

• which interpropositional relations are possible at the level of the speech act,
• how these are then coded.

Particular attention is paid to sequential position of subordinate clause, intonation, choice of conjunctions. Typically, for instance, only some of the causal conjunctions are possible at the level of the speech act. In Spanish, conditional constructions in which the protasis is at the level of the designatum use the conjunction si, while a translation of E3 would use the conjunction por si (because.of if) ‘just in case’.

Conversely, usability of a certain conjunction at the level of the speech act may be used as a test of its semantic nature which may, in semasiological perspective, shed some light on the semantic difference between this and other causal conjunctions.

References

Sweetser, Eve 1990, From etymology to pragmatics. Metaphorical and cultural aspects of semantic structure. Cambridge: Cambridge University Press (Cambridge Studies in Linguistics, 54).