Consider the sentence with 'and' in (17) and the related propositions in (18).
(17) Bill had breakfast and he went to work.
(18)
a. Bill had breakfast
b. He went to work
c. Bill went to work after he had breakfast
An expression of p ∧ q entails p and it entails q. However, in certain cases, an utterance seems to convey more than the meaning which is entailed. In (17), the order that the propositions appear in (breakfast first, work second) is suggestive of the underlying order in which the events occurred. That order also matches the real-world expectation about how working individuals' mornings typically unfold. However, the inference that the event described by the first conjunct happened before the event described by the second does not always hold. For example, (19) as an answer to a question about how Bill spent his winter break does not imply an order.
(19) Bill read 10 books and he got a lot of rest.
Note that the discourse context (what question an utterance is a reply to, who is speaking, who is being spoken to, etc.) matters a lot for assigning an interpretation to an utterance.
Here's another example. An expression of p ∧ q entails p ∨ q. This can be seen in (20) and the associated propositions in (21).
(20) Mary is taking syntax and Mary is taking semantics.
(21)
a. Mary is taking syntax
b. Mary is taking semantics
c. Mary is taking syntax or Mary is taking semantics
If the proposition expressed by (20) is true, then (21a,b,c) are all guaranteed to be true as well. However, if any of (21a,b,c) are uttered as an answer to the interrogative version of (20), additional meaning can be inferred. Imagine that someone asked "Is it true that Mary is taking syntax and Mary is taking semantics?"
KEY POINT: An utterance in context may receive additional meaning beyond the truth conditional semantic meaning.
A well-known question concerns the status of the word 'and' and the meaning of temporal order that often accompanies it. Gazdar (1979) argues against the autonomy of semantics with this (dated) example:
(22) To have a child and get married is worse than getting married and having a child.
We will return to the way that additional meaning arises when we look at implicature.
KEY POINT: We need something beyond semantics to capture speakers' intended meaning and listeners' inferred meaning.
To go on to section 2.4 "Summary", click here.