The elements which make up a sentence are: (1) the simple subject; (2) the simple predicate; (3) modifiers; (4) the complements,—direct object, predicate objective, predicate adjective, predicate nominative; and (5) the so-called independent elements,—the interjection, the vocative (or nominative of direct address), the exclamatory nominative, and various parenthetical expressions ([§ 501]).
449. The absolute essentials for a sentence are a substantive as subject and a verb as predicate ([§ 35]). By combining these two indispensable elements, in various ways, with modifiers and complements, the sentence may be extended to any length desired. Indeed, the sole limits are the constructive skill of the writer and the hearer’s ability to follow the thought without losing the thread.
In the present chapter, we shall consider how sentences are built up, or constructed. Our starting point in this study will be the simple sentence.
SIMPLE SENTENCES
450. The following statement is a simple sentence, for it contains but one subject and one predicate ([§ 46]):—
The polar bear | lives in the Arctic regions.
The framework or skeleton of this simple sentence consists of the subject noun bear (the simple subject) and the predicate verb lives (the simple predicate). To make the complete subject, bear takes as modifiers the two adjectives the and polar; to make the complete predicate, lives takes as modifier the adverbial phrase in the Arctic regions.
By attaching another simple subject to bear we make a compound subject. Similarly, we make a compound predicate by adding another verb ([§ 38]).
The polar bear and the walrus | live and thrive in the Arctic regions.
The compound subject is bear and walrus; the compound predicate is live and thrive. Both verbs are modified by the adverbial phrase in the Arctic regions. The sentence itself is still a simple sentence.