Veridicality

In linguistics, veridicality is the semantic property of a context to imply truth of its argument.

For example, the operator Fp = Yesterday, p is veridical: "Yesterday, Paul saw a snake" entails "Paul saw a snake". On the other hand, modality is nonveridical: "Paul may have seen a snake" does not entail "Paul saw a snake". Negation is not only nonveridical but antiveridical (a stronger property than nonveridicality): "Paul didn't see a snake" entails that "Paul saw a snake" is false.

Veridicality, nonveridicality and their subproperties are important for understanding of sensitivity of polarity items to the context of appearance. Modern theories explaining the licensing of polarity items based on these properties predict their behavior more precisely than prior works relying on downward entailment alone.

Formal definition

The formal definition of veridicality views the context as a propositional operator.

1. A propositional operator F is veridical iff Fp entails p: Fp → p; otherwise p is nonveridical.
2. Additionally, a nonveridical operator F is antiveridical iff Fp entails not p: Fp → ¬p.

For temporal and aspectual operators, the definition of veridicality is somewhat more complex:

• For operators relative to instants of time: Let F be a temporal or aspectual operator, and t an instant of time.
  1. F is veridical iff for Fp to be true at time t, p must be true at a (contextually relevant) time t′ ≤ t; otherwise F is nonveridical.
  2. A nonveridical operator F is antiveridical iff for Fp to be true at time t, ¬p must be true at a (contextually relevant) time t′ ≤ t.
• For operators relative to intervals of time: Let F be a temporal or aspectual operator, and t an interval of time.
  1. F is veridical iff for Fp to be true of t, p must be true of all (contextually relevant) t′ ⊆ t; otherwise F is nonveridical.
  2. A nonveridical operator F is antiveridical iff for Fp to be true of t, ¬p must be true of all (contextually relevant) t′ ⊆ t.

Nonveridical operators

Nonveridical operators typically license the use of polarity items, which in veridical contexts normally is ungrammatical:

* John saw any students. (The context is veridical.)

John didn't see any students. (The context is nonveridical.)

Downward entailment

All downward entailing contexts are nonveridical. Because of this, theories based on nonveridicality can be seen as extending those based on downward entailment, allowing to explain more cases of PI licensing.

Downward entailment predicts that polarity items will be licensed in the scope of negation, downward entailing quantifiers like few N, at most n N, no N, and the restriction of every:

No students saw anything.

John didn't see anything.

Few children saw anything.

Every student who saw anything should report to the police.

Non-monotone quantifiers

Quantifiers like exactly three students, nobody but John, and almost nobody are non-monotone (and thus not downward entailing) but nevertheless admit any:

 % Exactly three students saw anything.

Nobody but John saw anything.

Almost nobody saw anything.

Hardly and barely

Hardly and barely allow for any despite not being downward entailing.

John hardly talked to anybody. (Does not entail "John hardly talked to his mother".)

John barely studied anything. (Does not entail "John barely studied linguistics".)

Questions

Polarity items are quite frequent in questions, although questions are not monotone.

Did you see anything?

Although questions biased towards the negative answer, such as "Do you [even] give a damn about any books?" (tag questions based on negative sentences exhibit even more such bias), can sometimes be seen as downward entailing, this approach cannot account for the general case, such as the above example where the context is perfectly neutral. Neither can it explain why negative questions, which naturally tend to be biased, don't license negative polarity items.

In semantics which treats a question as the set of its true answers, the denotation of a polar question contains two possible answers:

[[Did you see John?]] = { you saw John ∨ you didn't see John }

Because disjunction p ∨ q entails neither p nor q, the context is nonveridical, which explains the admittance of any.

Future

Polarity items appear in future sentences.

John will buy any bottle of wine.

The children will leave as soon as they discover anything.

According to the formal definition of veridicality for temporal operators, future is nonveridical: that "John will buy a bottle of Merlot" is true now does not entail that "John buys a bottle of Merlot" is true at any instant up to and including now. On the other hand, past is veridical: that "John bought a bottle of Merlot" is true now entails that there is an instant preceding now at which "John buys a bottle of Merlot" is true.

Habitual aspect

Likewise, nonveridicality of the habitual aspect licenses polarity items.

He usually reads any book very carefully.

The habitual aspect is nonveridical because e.g., that "He is usually cheerful" is true over some interval of time does not entail that "He is cheerful" is true over every subinterval of that. This is in contrast to e.g., the progressive aspect, which is veridical and prohibits negative polarity items.

Generic sentences

Non-monotone generic sentences accept polarity items.

Any cat hunts mice.

Modal verbs

Modal verbs create generally good environments for polarity items:

John may talk to anybody.

Any minors must be accompanied by their parents.

The committee can give the job to any candidate.

Such contexts are nonveridical despite being non-monotone and sometimes even upward entailing ("John must tango" entails "John must dance").

Imperatives

imperatives are roughly parallel to modal verbs and intensional contexts in general.

Take any apple. (cf. "You may/must take any apple", "I want you to take any apple".)

Protasis of conditionals

Protasis of conditionals is one of the most common environments for polarity items.

If you sleep with anybody, I'll kill you.

Directive intensional verbs

Polarity items are licensed with directive propositional attitudes but not with epistemic ones.

John would like to invite any student.

John asked us to invite any student.

* John believes that we invited any student.

* John dreamt that we invited any student.

References

• Giannakidou, Anastasia (2002). "Licensing and Sensitivity in Polarity Items: From Downward Entailment to Nonveridicality". In Andronis, Maria; Pycha, Anne; Yoshimura, Keiko (PDF format; Adobe Acrobat required). CLS 38: Papers from the 38th Annual Meeting of the Chicago Linguistic Society, Parasession on Polarity and Negation. http://home.uchicago.edu/~giannaki/pubs/cls.giannakidou.pdf. Retrieved December 15, 2011.