{{Short description|Linguistic sentence with null subject}} A '''pro-sentence''' is a function word or expression that substitutes for a whole sentence whose content is recoverable from the context. A pro-sentence is a kind of pro-form and is therefore anaphoric.

==Overview== In English, ''yes'', ''no'' and ''okay'' are common pro-sentences. In response to the question "Does Mars have two moons?", the sentence "Yes" can be understood to abbreviate "Mars does have two moons."

Pro-sentences are sometimes seen as grammatical interjections, since they are capable of very limited syntactical relations. But they can also be classified as a distinct part of speech, given that (other) interjections have meanings of their own and are often described as expressions of feelings or emotions.

=== Yes and no === {{main|Yes and no}} In some languages, the equivalents to ''yes'' and ''no'' may substitute not only a whole sentence, but also a part of it, either the subject and the verb, or the verb and a complement, and can also constitute a subordinate clause.

The Portuguese word ''sim'' (''yes'') gives a good example:

:Q: {{lang|pt|Ela está em casa?}} {{gloss|Is she at home?}} :A: {{lang|pt|Acredito '''que sim'''.}} {{gloss|I believe '''that she is.'''}} (literally, '''that yes''')

:{{lang|pt|Ela não saiu de casa, mas '''o John sim'''.}} :{{gloss|She didn't leave home, but '''John did.'''}} (literally, '''John yes''').

In some languages, such as English, ''yes'' rebuts a negative question, whereas ''no'' affirms it. However, in Japanese, the equivalents of ''no'' ({{Transliteration|ja|iie, uun, (i)ya}}) rebut a negative question, whereas the equivalents of ''yes'' ({{Transliteration|ja|hai, ee, un}}) affirm it.

:Q: {{lang|ja|わかりません でした か？}} {{Transliteration|ja|Wakarimasen deshita ka?}} {{gloss|Did you not understand?}} :A: {{lang|ja|はい、 わかりません でした。}} {{Transliteration|ja|Hai, wakarimasen deshita.}} {{gloss|No, I didn't.}}, literally {{gloss|That's right, I didn't understand}}

Some languages have a specific word that rebuts a negative question. German has {{lang|de|doch}}, French has {{lang|fr|si}}, Norwegian has {{lang|no|jo}}, Danish has {{lang|da|jo}}, Swedish has {{lang|sv|jo}}, and Hungarian has {{lang|hu|de}}. The English words "yes" and "no" were originally only used to respond to negative questions, while "yea" and "nay" were the proper responses to affirmative questions; this distinction was lost at some time in Early Modern English{{Citation needed|date=June 2024}}.

:Q: {{lang|de|Bist du nicht müde?}} {{gloss|Aren't you tired?}} :A: {{lang|de|Doch. Ich gehe bald schlafen.}} {{gloss|Yes. I'm about to go to sleep.}}

== In philosophy<!--'Prosententialism' redirects here--> == The '''prosentential theory of truth'''<!--boldface per WP:R#PLA--> developed by Dorothy Grover,<ref>Grover, Belnap, Camp. "The Prosentential Theory of Truth", Philosophical Review 1970.</ref> Nuel Belnap, and Joseph Camp, and defended more recently by Robert Brandom, holds that sentences like ''"p" is true'' and ''It is true that p'' should not be understood as ascribing properties to the sentence "p", but as a pro-sentence whose content is the same as that of "p." Brandom calls " . . .is true" a pro-sentence-forming operator.<ref>Brandom, ''Making it Explicit'', 1994.</ref>

== See also == * {{annotated link|Null-subject language}} * {{annotated link|Null subject parameter}}

==References== {{reflist}}

==External links== *{{wti}}

{{Lexical categories|state=collapsed}}

Category:Parts of speech