Detached parts of the sentence are those secondary parts which assume a certain grammatical and semantic independence. This phenomenon is due to their loose connection with the words they modify.
Loose connection may be due to the position of these words, the way they are expressed, their meaning, or the speaker’s desire to make them prominent.
The detached adverbial modifier.
Any part of speech used in the function of an adverbial modifier may be detached, which accounts for the comma that separates it from the rest of the sentence.
(In her excitement, Maria jammed the bedroom-door together.)
An adverbial modifier expressed by the Nominative Absolute Participial Construction or any other absolute construction is generally detached.
(The train coming in a minute later, the two brothers parted and entered their respective compartments.)
Of all the kinds of adverbial modifiers that of attendant circumstances is most apt to become detached.
(He came in, with a large parcel under his arm)
A detached attribute can modify not only a common noun as an ordinary attribute does but also a proper noun and a pronoun.
(It was a wide white building, one storey high)
The detached object.
The prepositional indirect object is often detached.
(She does not change — except her hair.)
The independent elements of the sentence are words arid word-groups which are not grammatically dependent on any part of the sentence.
1. Interjections, such as ah, oh, hurrah, eh, hallo, goodness gracious, good heavens, etc.
(“Oh gracious me! that innocent Toots,” returned Susan hysterically.)
2. Direct address.
(Good morning, sweet child!)
A parenthesis either shows the speaker’s attitude towards the thought expressed in the sentence or connects a given sentence with another one, or summarizes that which is said in the sentence. A parenthesis is connected with the rest of the sentence rather semantically than grammatically. No question can be put to it. Very often it is detached from the rest of the sentence and consequently it is often separated from it by commas or dashes.
(To be sure, Morris had treated her badly of late.)
A parenthesis can be expressed by:
1. Modal words, such as indeed, certainly, assuredly, decidedly, in fact, truly,, naturally, surely, actually, possibly, perhaps, evidently, obviously, maybe.
(Evidently, he was not a man, he must be some other kind of animal.)
2. Adverbs which to a certain extent serve as connectives, such as firstly, secondly, finally, thus, consequently, then, anyway, moreover, besides, still, yet, nevertheless, otherwise, notwithstanding, therefore, etc.
(He mightn’t like it. Besides, uncle Soames wants to get back, I suppose.)
3. Prepositional phrases, such as in a word, in truth, in my opinion, in short, by the by, on the one hand, on the contrary, at least, etc.
(Everybody has his own problem. Mine is practically worthless, for instance.)
4. Infinitive and participial phrases, such as to be sure, to tell the truth, to begin with, generally speaking, strictly speaking, etc.
(Sarah; my dear, comparatively speaking, you’re safe.)
Two or more parts of the sentence having the same function and referring to the same part of the sentence are called homogeneous parts of the sentence. They are linked either by means of coordinating conjunctions or asyndetically.
There can be:
1. Two or more homogeneous subjects to one predicate.
(To her extreme relief, her father and sisters appeared.)
2. Two or more homogeneous predicates to one subject.
(a) Simple predicates.
(That gentleman started, stared, retreated, rubbed his eyes, stared again and finally shouted: “Stop, stop!”)
(b) A compound verbal modal predicate with homogeneous parts within it.
(Thousands of sheets must be printed, dried, cut.)
(c) A compound verbal aspect predicate with homogeneous parts within it.
(First he began to understand and then to speak English.)
(d) A compound nominal predicate with several predicatives within it.
(The sky was clear, remote, and empty)
3. Two or more attributes, objects, or adverbial modifiers to one part of the sentence.
(The unlighted, unused room behind the sitting-room seemed to absorb and even intensify the changing moods of the house-ATTRIBUTES)
(He could imitate other people’s speech, their accent, their mannerisms, their tone-DIRECT OBJECTS)
(He talked of Spain, his sunstroke, Val’s horses, their father’s health-PREPOSITIONAL INDIRECT OBJECTS)
(She extended a slender hand and smiled pleasantly and naturally-ADVERBIAL MODIFIERS OF MANNER)
(But I saw nothing moving, in earth or sky-ADVERBIAL MODIFIERS OF PLACE)