An apposition is a special kind of attribute which is expressed by a noun (with or without accompanying words) which characterizes or explains the word modified by giving the person or thing another name.

There are two kinds of apposition,

1. the close apposition and
2. the loose or detached apposition.

A close apposition is not separated by commas and stands in close connection with the word modified. These word groups generally consist either of the names of a person and a noun denoting a title, rank, profession, or the name of a person and a noun denoting relationship, or a geographical name and some common noun, e.g. Professor Brown, Captain Marryat, Aunt Polly, President Roosevelt, etc.

Even Aunt Ann was there. (Galsworthy)
Professor Sommerville practised what he preached. (Carter)

In these word groups the noun modified is the name of a person or a geographical name, the first component is a common noun in apposition.

NOTE: In case the common noun is preceded by a possessive or a demonstrative pronoun, it becomes more important and acquires a stronger stress. Consequently the relation between the components of the word group is reversed. The first component is modified by the name of a person or a geographical name which is an apposition:

That boy Peter has a literary turn of mind. He is sure to become a writer.

Sometimes the apposition consists of the preposition of + noun, e. g. the town

of Daventry, the city of London.

A loose apposition is not so closely connected with the noun. It is always separated by commas and has a stress of its own.

Dr. Winchcliffe, my predecessor, was a classmate of my father’s. (Sanborn)

With her elder and younger sisters she lived now in the house of Timothy, her sixth and youngest brother, on the Bayswater Road. (Galsworthy)