"Once upon a time there was a very lazy boy. The lad would sleep till the mid-day sun woke him and he had to crawl out of bed." And so on. Very simple - but grammatically so subtle!
Keep your eye on the hero and the words used to refer to him. First he is "a very lazy boy", which introduces him by describing him. Then we have a shorter noun phrase "the lad", and lastly a series of pronouns "him" and "he":
a very lazy boy -- the lad -- him -- he
This is a reference chain - a chain of words running through the text which all pick out the same character.
Reference chains are an important part of cohesion in text-level grammar, so KS3 writers should know how to use them skilfully. Not that they're starting from scratch - far from it. Reference chains are part of everyday conversation, but writing is a bit different, and mature writing can be very different.
The basic principle is rather like a formula for writing a play.
First put each character 'on stage' by giving a description. This should give enough detail to distinguish this character from everyone else (or at least from everyone else who might occur to the listener/reader), and it may be indefinite (introduced in this case by "a", the indefinite article).
Use definitepronouns, nouns and noun phrases to refer to someone who is already on stage. In our story we have the definite noun phrase "the boy", and then the pronouns "him" and "he" which are also definite.
All very simple, but so far this is just the grammar of ordinary conversation. It becomes especially interesting when issues of cohesion are explored in literature. In fairy tales we expect the traditional reference chains which move from indefinite to definite, from nouns to pronouns: “A girl called Little Red Riding Hood set off from home. She was …”.
In the hands of expert writers sophisticated literary effects are created. Take the opening to Oliver Twist. The first link is a monster noun phrase:
it -- the child -- Oliver Twist -- Oliver -- he -- Oliver -- he -- Oliver -- Oliver.
Why so few pronouns? Try using pronouns instead of "Oliver" -- better or worse?
Cohesion is an important element in the way texts are organised and reference chains an interesting aspect for our pupils to explore, both as readers and writers. If you want more about them, go to 'anaphora' in www.phon.ucl.ac.uk/home/dick/tta/KS3.htm.