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Explore the English Language
Mother Tongue: The English LanguageMother Tongue: The English Language by Bill Bryson
Buy used from: £1.00
Whether or not school put you off, the English Language truly is intensely interesting. If you don't agree, this great introduction should change your mind while simultaneously amusing you.
The Adventure of EnglishThe Adventure of English by Melvyn Bragg
Buy new: £6.69 / Used from: £0.13
If you enjoyed the above book, this should be next on your list to more fully explore the history of the English language. Informative and easy to read.
The Stories of EnglishThe Stories of English by David Crystal
Buy new: £6.49 / Used from: £3.75
Similar in scope to the above book and a worthy alternative or supplementary reading depending on your level of interest.
Troublesome WordsTroublesome Words by Bill Bryson
Buy used from: £2.00
More Bryson but if you want to understand the subtleties of English and avoid making mistakes this is really worthwhile. Plus it's witty and illustrated with great examples.
Shorter Oxford English Dictionary [With CDROM]Shorter Oxford English Dictionary [With CDROM] by William R. Trumble
Buy new: £78.51 / Used from: £82.73
Pricey but if you can afford it this is indubitably the best 1-2 volume dictionary out there.
The RSC Shakespeare: The Complete WorksThe RSC Shakespeare: The Complete Works by William Shakespeare
Buy new: £25.20 / Used from: £18.84
The best Complete Works of Shakespeare. All difficult words and phrases are explained on the same page; it doesn't shy away from the raciness; good introductions. Easy and delightful to read.
Rediscover GrammarRediscover Grammar by Prof David Crystal
Buy new: £12.99 / Used from: £9.52
This looks like the best of the bunch of grammar books and it is well worth honing your skills. I got all the basics off the internet but should probably invest in this myself.