Why sub-titles help

A sub-title states the main idea of one section of a long piece of writing. With sub-titles, readers can see the sub-topics at a glance, and find the part they want. Sub-titles also break up long passages, making them easier and less tiring to read.

Many newspaper articles also have a line in italics just under the headline, called a standfirst. It sums up the whole article in one sentence, to draw the reader in.

The book's practice article is about the state of Indian cities. It opens with the nineteenth-century writer Engels' picture of the filthy industrial cities of England, and says that many Indian cities still look like that today.

Its first section, which could be titled 'Urban Decay', recalls the plague in Surat in 1994, and the neglect of waste management by governments.

A good sub-title is like a signpost: a few words that tell the reader what lies ahead.