You would be mad. Here is why:
English is a core subject. All teenagers must study it through to the end of Year 11. This means that your class size will always be close to 30, unlike ‘option’ subjects such as Geography, Music, etc, where classes are smaller because you choose these subjects.
A lot of teenage boys despise reading and their dislike of reading is exceeded only by their hatred of writing. No matter how hard you try to make your lessons fun and engaging, you’ll be battling this resistance and getting more than your share of behaviour probs.
The marking of a core, written subject will completely obliterate all your evenings and weekends.
The GCSE now has four exams (Paper 1 English Language; Paper 2 English Language; Paper 1 English Lit; Paper 2 English Lit). Your own time, outside 9am-3pm, from December to April, will be spent marking mock exams.
Parents will be emailing and phoning to complain that their child isn’t meeting his/ her predicted grade, when the reason for this is that the child does no work.
Every parent will want to see you at parents’ evenings because it’s a core subject, and they will harass you about progress and attainment, even if the child puts nothing into their work and is disruptive.
i could go on, but English has the biggest workload of all teaching jobs. I did it for 15 years and had no time to pursue fitness, friends, hobbies.
Don’t do it.