Cambridge Grammar of English Hardback with cd-rom a comprehensive Guide

NP1

NP2

NP3

Madge, one of the secretaries at work, her daughter got married last week.

My friend, Janet, her sister has just emigrated to Brazil.

[a Ford Escort is a model of car]

His cousin in London, her boyfriend, his parents bought him a Ford Escort.

Such strings of noun phrases help to provide orientation for the listener, who can

then more easily identify the main topic. They often lead the listener from given or

known information to new topical information. Headers of this kind do not

normally occur in written English, and though they may look strange when

transcribed and written on the page, they are normal, frequent, and pass without

comment by participants. 

Headers may also be non-finite clauses:

Going round museums and art galleries, it’s what my mum and dad like doing. 

Walking into that room, it brought back a load of memories.