At first sight, it may appear strange that increasing the number of writing assignments students complete does not materially affect the quality of their writing skills. More than one essay or letter a week would not seem to offer any benefit commensurate with the effort they put into it. By contrast, reading a lot and often does pay off.
There are three compelling reasons why this should be the case. Firstly, language is truly complex and, at a certain level of attainment, we are more and more dealing with exceptions to standard formulas. We can, for instance, use a future verb form directly after 'if'; the present perfect can refer to the past, present and future; articles can precede proper nouns. And that's only when we look at grammatical structures. The nuances of meaning with phrasal verbs defy classroom instruction and register is a perennial challenge for learners. Reading, though, opens up examples of any and all these anomalies.
Writing, by contrast, does not. We might want to practise a new structure and that's all to the good but how can we develop a wider repertoire by relying on our own knowledge? Common sense tells us that we need to be exposed to new forms, collocations and words. And that's where reading comes in.
Then, there's the sheer amount of time that we spend reading compared to writing. Whether it's labels on cans of soup, SMSes, FB posts or novels, reading is an integral part of each and every day, far more so than writing. Estimates as to the ratio of time spent reading as opposed to writing start at 25:1.
And, finally, we need to consider that models are essential to writing development. If we need to improve our academic writing, then we imitate the language in journals. Better our facility with penning stuff for magazines? - then, read magazines. But again it's reading - not writing - that provides the material for us to refine a style of our own.
For more on writing skills, look up Krashen's 'Power of Reading' (2006, 2nd ed.)
English stories and articles for reading and listening practice
Extensive reading and listening helps you learn and practice English. Listen and read to improve your English skills.