partly on stylistic factors.
Apposition has been often regarded as a special kind of attribute, and
sometimes as a secondary part of a sentence distinct from an attribute. Apposition
is a word or phrase referring to a part of the sentence expressed by a noun, and
explaining and specifying its meaning by giving it another name. Appositions are
usually expressed by nouns.
The major problem concerning the secondary sentence parts is caused by the
fact that characteristic features of each of the three types are not clearly defined,
therefore describing a given word or phrase as an object or an attribute in some
cases, or describing it as an object or an adverbial modifier, in others, often proves
to be a matter of personal opinion or predilection.
There are some elements of the sentence which are neither its main parts,
nor any of the usual secondary ones. They are the direct address and the
parenthesis. (Refer to the book by Ilyish for more information).
