Implicatures

Implicature is a technical term in the pragmatics subfield of linguistics, coined by Paul Grice, which refers to what is suggested in an utterance, even though not expressed nor strictly implied (that is, entailed) by the utterance. For example, the sentence "Mary had a baby and got married" strongly suggests that Mary had the baby before the wedding, but the sentence would still be strictly true if Mary had her baby after she got married. Further, if we add the qualification "— not necessarily in that order" to the original sentence, then the implicature is cancelled even though the meaning of the original sentence is not altered.

Conversational implicature
Paul Grice identified three types of general conversational implicature:

1. The speaker deliberately flouts a conversational maxim to convey an additional meaning not expressed literally.

For instance, a speaker responds to the question "How did you like the guest speaker?" with the following utterance:

Well, I’m sure he was speaking English.

If the speaker is assumed to be following the cooperative principle, in spite of flouting the Maxim of Quantity, then the utterance must have an additional nonliteral meaning, such as: "The content of the speaker’s speech was confusing."

2.The speaker’s desire to fulfill two conflicting maxims results in his or her flouting one maxim to invoke the other. For instance, a speaker responds to the question "Where is John?" with the following utterance:

He’s either in the cafeteria or in his office.

In this case, the Maxim of Quantity and the Maxim of Quality are in conflict. A cooperative speaker does not want to be ambiguous but also does not want to give false information by giving a specific answer in spite of his uncertainty. By flouting the Maxim of Quantity, the speaker invokes the Maxim of Quality, leading to the implicature that the speaker does not have the evidence to give a certain answer to where John is.

3.The speaker invokes a maxim as a basis for interpreting the utterance. In the following exchange:

Do you know where I can get some gas? There’s a gas station around the corner.

The second speaker invokes the Maxim of Relevance, resulting in the implicature that “the gas station is open and one can probably get gas there”

Scalar Implicature
According to Grice (1975), another form of conversational implicature is also known as a scalar implicature. This concerns the conventional uses of words like "all" or "some" in conversation.

I ate some of the pie.

This sentence implies "I did not eat all of the pie." While the statement "I ate some pie" is still true if the entire pie was eaten, the conventional meaning of the word "some" and the implicature generated by the statement is "not all".

Conventional implicature
Conventional implicature is independent of the cooperative principle and its maxims. A statement always carries its conventional implicature.

Joe is poor but happy.

This sentence implies poverty and happiness are not compatible but in spite of this Joe is still happy. The conventional interpretation of the word "but" will always create the implicature of a sense of contrast. So Joe is poor but happy will always necessarily imply "Surprisingly Joe is happy in spite of being poor". Conventional implicatures cannot be cancelled (unlike conversational implicatures, which can be).

Implicature vs entailment
This can be contrasted with cases of entailment. For example, the statement "The president was assassinated" not only suggests that "The president is dead" is true, but requires that it be true. The first sentence could not be true if the second were not true; if the president were not dead, then whatever it is that happened to him would not have counted as a (successful) assassination. Similarly, unlike implicatures, entailments cannot be cancelled; there is no qualification that one could add to "The president was assassinated" which would cause it to cease entailing "The president is dead" while also preserving the meaning of the first sentence.

Implicature and implication
The specialized term implicature was coined by Paul Grice as a technical term in pragmatics for certain kinds of inferences that are drawn from statements without the additional meanings in logic and informal language use of "implication".