# What is one-place predicate and two-place predicate?

When I read some linguistic articles, I encountered two names. One is called a "one-place predicate" and the other is a "two-place" predicate. So what are the definitions of these two concepts and what are the differences between them? Can anyone provide me with some examples to help me understand that?

• It looks like it's another name for the intransitive and transitive verbs, the number of “places” being the same as the number of arguments — we can distinguish predicates in terms of how many arguments they involve: sleep is a one-place predicate: you sleep, while see is a two-place predicate involving two arguments: you see me. Aug 30, 2023 at 13:45
• First of all, do you understand the meaning of "predicate" on its own? That'll be important for the answer.
– Draconis
Aug 30, 2023 at 14:47
• Note that there are two slightly different senses in which the word "predicate" is typically used; in papers on syntax it usually means a verb, whereas in formal semantics the notion of a predicate also subsumes nouns, adjectives, and in general anything that expresses a property of or relation between individuals. Aug 30, 2023 at 18:28
• Predicate is a logical term roughly equivalent to a verb or verb phrase in syntax. Like functions in mathematics, predicates in logic have arguments (`KICK` (`BILL`, `BALL`) means Bill kicks the ball, roughly. It's a skeletal account of the syntax using only some of the meaning. One-, two-, and three-place predicates have the appropriate number of arguments. See the logic study guide for details. Aug 30, 2023 at 19:51

A predicate is an expression that expresses a property of or relation between individuals, i.e. something that evaluates to true or false if you combine it with an appropriate number of individuals. In the broader, semantic sense, predicates can take the form of verbs, nouns and adjectives, or complex expressions involving in addition function words like "is", "a", "of" in English, though usually in the syntax literature, the term predicate is only used when talking about verbs.

The placeness (also known as valency) is about how many "slots" the predicate has that are to be filled (with so-called arguments) to become a sentence. "intransitive", "transitive" and "ditransitive" are used as synonyms for one-, two- and three-place, respectively.

Eg "_ stinks", "_ is a cat", "_ is red" are examples of one-place (intransitive) predicates.
"_ loves _", "_ is a friend of _", "_ is afraid of _" are examples of two-place (transitive) predicates.
"_ gives _ to _" is a three-place (ditransitive) predicate.
To my knowledge there is no clear evidence of four-or-more -place predicates in natural languages.

A "one-place" predicate is a predicate that has one "argument", in the languages we know this is the subject of the verb. A "two-place" predicate is, in a sense, a transitive verb, with two arguments.

A reason for avoiding the terms intransitive / transitive can be that this may have overtones that have to do with the meanings of the verbs. So, depending on the specific tradition, not all "two-place verbs" may in fact be called transitive, but transitive may be confined to verbs with "doer" and "undergoer" as arguments. At least in the German tradition, clauses like "this idea scares me" would not be called "transitive", even though there is an accusative object. But there's confusion and others would use the term "transitive" differently. -- Likewise "intransitive" may get in the way of the unaccusative hypothesis (look up wikipedia if necessary).

So: "1/2-place" makes it clear that no such additional restrictions are intended and you simply count the number of arguments that appear with a verb.

• I changed complement" to "argument", in case someone has a different notion of "complement" (in one sense, this is synonymous, but in another sense "complement" might be taken to mean "object"?) Was there a misunderstanding about this? Aug 31, 2023 at 10:04