We have already seen that the major functional unit of speech, the
sentence, has, like the word, a psychological as well as a merely
logical or abstracted existence. Its definition is not difficult. It is
the linguistic expression of a proposition. It combines a subject of
discourse with a statement in regard to this subject. Subject and
"predicate" may be combined in a single word, as in Latin _dico_; each
may be expressed independently, as in the English equivalent, _I say_;
each or either may be so qualified as to lead to complex propositions of
many sorts. No matter how many of these qualifying elements (words or
functional parts of words) are introduced, the sentence does not lose
its feeling of unity so long as each and every one of them falls in
place as contributory to the definition of either the subject of
discourse or the core of the predicate[7]. Such a sentence as _The mayor
of New York is going to deliver a speech of welcome in French_ is
readily felt as a unified statement, incapable of reduction by the
transfer of certain of its elements, in their given form, to the
preceding or following sentences. The contributory ideas of _of New
York_, _of welcome_, and _in French_ may be eliminated without hurting
the idiomatic flow of the sentence. _The mayor is going to deliver a
speech_ is a perfectly intelligible proposition. But further than this
we cannot go in the process of reduction. We cannot say, for instance,
_Mayor is going to deliver_.[8] The reduced sentence resolves itself
into the subject of discourse--_the mayor_--and the predicate--_is going
to deliver a speech_. It is customary to say that the true subject of
such a sentence is _mayor_, the true predicate _is going_ or even _is_,
the other elements being strictly subordinate. Such an analysis,
however, is purely schematic and is without psychological value. It is
much better frankly to recognize the fact that either or both of the two
terms of the sentence-proposition may be incapable of expression in the
form of single words. There are languages that can convey all that is