How to define a purpose

In the assessment, you’ll be asked to define the writer’s purpose. Purposes usually begin with the word ‘to’. A common mistake is to provide an answer such as the one below (it doesn’t matter what the article was, just read the answers):

The purpose of the article was about the possibility of banning smoking in restaurants.

This can’t be a correct answer, as a purpose should have a ‘to’ word in it. A better answer is this one:

The purpose of the article was to inform readers about the possibility of banning smoking in restaurants.

Another good answer would be:

The writer’s purpose was to argue that smoking should be banned in restaurants.