Presuppositions in Spoken Discourse

Accommodation and Presupposition
The trigger types show differences in how often they occurred under
embeddings. It-clefts are somewhat special among the triggers studied here in that
they are associated with a particular syntactic form, rather than having a
presupposition that is localized on a lexical item, and this may make it more
awkward to embed, a potential cause for the low number of embedded examples
found.
Definite NPs seem to almost always be globally accommodated. One
explanation could be that we don’t tend to introduce concrete individuals into a
discourse by using a presupposition trigger unless they are meant to be assumed to
be known, or they are shared information with the hearer, etc. In a hypothetical or
conditional discussion where the presupposition is not bound, definite NPs are
likely to project out. Also this could be an effect of the relationship between
hypothetical discussions and semantic individuals introduced within them.
Most hypothetical discussions are short-lived, local, generally limited in life
to the current discourse context plus the participants, i.e. we don’t often continue
hypothetical discussions from conversation to conversation. Because of this,
individuals that are hypothetical can seldom fall under the category of hearerknown
but non-salient, they are generally introduced for the first time within that
particular context, and similar to definite NP usage in non-embedded contexts they
will tend to be introduced by indefinite nouns or indefinite noun phrases.
Thereafter, subsequent references with a definite NP will get bound. This group
will never make it to the main context. When definite NPs are used to introduce
hypothetical items these are generally partially resolvable to other information in
the hypothetical context, and should therefore more appropriately be considered
bridging. But if a definite description is used in an embedded context and can’t be
bound or resolved through bridging, it will be accommodated in the main context.
Factives are different. In a hypothetical context, for example, an if-then
clause, if a factive is used in the conditional clause, there is a good chance that it
will not project out. The point of the hypothetical context is to discuss information
about how the world could be. The point of using a factive is to discuss who did or
didn’t notice, know, regret, realize etc., the fact presented as the complement at a
particular time. Factives are able to be used to introduce hearer-new information
that is also the point of the utterance, or what is focused or foregrounded. There
may be some sort of relationship about being able to be the main point of an
utterance which encourages the ability to function independently in an embedded
context, but I am not quite sure yet how to describe this. But I think this feature
will encourage/support the speaker using the presuppositions induced by these
triggers to be locally accommodated.
In factive presupposition, we can also separate the attitude towards the fact
from knowledge about the actual fact. This separation of the asserted and the
presupposed meaning, where each can make a significant new contribution to the
discourse (as shown in section 5.2) is something that is missing from aspectual
verbs.
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