Строй современного английского языка

Chapter XXIX
THE APPOSITION, DIRECT ADDRESS, PARENTHESES, AND INSERTIONS. LOOSE PARTS
Now we come to speak of some parts of a sentence whose position in its structure has been variously treated by different authors. One of these is the apposition.
THE APPOSITION
It has been often regarded as a special kind of attribute, and sometimes as a secondary part of a sentence distinct from an attribute.
By apposition we mean a word or phrase referring to a part of the sentence expressed by a noun, and giving some other designation to the person or thing named by that noun. If the noun denotes a person, the apposition will often be a word or phrase naming the title, or profession, or social position of the person, etc., as the word Captain in the sentence, For a moment, Melanie thought how nice Captain Butler was. (M. MITCHELL) Concerning the apposition the same question may arise as concerning the attribute, namely, whether it is not part of a phrase rather than of a sentence, and arguments similar to those applied to the attribute may be put forward here.
As to the relation between an apposition and an attribute, there seems to be no convincing reason for considering the apposition a special kind of attribute. An apposition appears to have distinctive features strong enough to establish it as a separate secondary part: it is always expressed either by a noun, or by a phrase centred around a noun, and characterises the person or thing in a way different from that of an attribute. This will become clear if we compare the phrases stone wall and President Roosevelt: the relations between their components are entirely different.
THE DIRECT ADDRESS
There are some elements of the sentence which are neither its main parts, nor any of the usual secondary ones.
These are the direct address and the parenthesis.^1
1 The term "parenthesis" has two meanings: it may denote either a part of the sentence or a punctuation mark also called brackets. We will here use the term in its first sense.

232 The Apposition, Direct Address, Parentheses, and Insertions
T he direct address and the parenthesis are often said to be outside the sentence, in the sense that they are not an integral part of its structure but are, as it were, added to it "from the outside". ¹ This view, however, seems hardly justified and it is based on a rather too narrow view of the structure of a sentence. If we were to take the term "outside the sentence" at its face value, we should have to omit these elements, for example, when asked to read a sentence aloud. This is never done, and should not be done. By "structure of the sentence" we should mean the whole of a sentence, with all the elements which it may contain, with their varying degrees of organic unity. In this sense, then, the direct address is no less a part of the sentence than any other word or phrase.
The direct address is a name or designation of the person or persons (or, occasionally, thing or things) to whom the speech or writing is addressed. We should not include in a definition of direct address the purpose of its use, as is done occasionally in grammars. ² The purpose may be different in different circumstances, but this does not alter the fact that it is a direct address in all cases.
The direct address may consist of one word or of a phrase. If it is one word, this may be the person's name, or profession, or title, or it may denote a relationship between the person addressed and the speaker. If it is a phrase, this may again be any of the types just mentioned, or it may be some emotional address, whether friendly, as my dear fellow, or hostile, as you swine, you old rascal, etc. In the latter case, it is quite clear that the speaker's purpose in using a direct address is to express his attitude towards the person spoken to, whether it be friendly or otherwise. A few examples from modern fiction will do well to illustrate the various possibilities in the structure and function of the direct address: Heathenish woman, how right they were to give you that outlandish name. (A. WILSON) The adjective heathenish of course expresses very violent emotion on the part of the speaker towards the person addressed. Quite a different emotional note is struck in the following sentence: Jennie, darling, you're looking very pretty," he said. (Idem) The name Jennie as such is neutral in tone, but the second part of the direct address, darling, of course expresses the speaker's emotional attitude toward the person addressed.
The emotional range of the words and phrases used in direct address can of course be very wide indeed, and this deserves close study from a lexical and stylistic viewpoint, but it does not affect the grammatical aspect of the matter.
¹ For this view, see, for instance, Грамматика русского языка, т. II, ч. 2, стр. 122.
² See, for example, M. Ganshina and N. Vasilevskaya, English Grammar, 7th ed., 1951, p. 320.