The term predicate traditionally refers to

the part of a sentence that characterizes the subject.

In “Sally kissed Fred,” “Sally” is the subject

and “kissed Fred” is the predicate. Philosophers

and logicians extend this notion, so that a sentence

with one or more singular terms removed is

a predicate. Predicates are 1-place, 2-place, and so

forth, depending on the number of singular

terms needed to make a sentence. A predicate is

said to be true of an object or sequence of objects

if a true sentence would result if terms referring

to that object or those objects were inserted.

From our example, we can get these predicates:

1. (1) kissed Fred.

2. (1) kissed (2)

3. Sally kissed (2)

4. (1) kissed (1).

(1) is a 1-place predicate, true of Sally and

whoever else has kissed Fred. Predicate (2) is a

2-place predicate, true of the pair of Sally and

Fred, and any other pair, the first of which has

kissed the second. Number (3) is a 1-place predicate,

true of Fred and others Sally has kissed.

And (4) is a 1-place predicate, because it only

takes one referring expression to complete the

sentence, although it must be inserted twice. It is

true of people who have kissed themselves.

The notion of a predicate does not necessarily

fit very well with the categories linguists use to

describe the structure of sentences. For example,

the words Sally kissed, which remain after Fred is

removed from our sentence, giving predicate (3),

are not usually considered a syntactic part of the

original sentence.

premise See deductive argument.