Spelling and Proofreading Accuracy
What you must know
Spelling and proofreading marks are easy to gain and easy to lose. Learn the patterns: double the final consonant before a suffix when the stress falls on the last syllable ('beginning', 'preferred'); drop a silent 'e' before a vowel suffix ('hoping'); apply 'i before e except after c' with its exceptions; and keep British spelling consistent ('colour', 'realise', 'centre'). Know the homophones: their, there and they're; to, too and two; practice and practise; affect and effect; loose and lose.
Traps
The most frequent errors are homophones, missing apostrophes, comma splices, and words accidentally omitted when copying a sentence for editing. Watch for inconsistency: mixing 'organise' and 'organize' in one piece looks careless. In proofreading questions, correct only what is wrong, because rewriting a correct sentence can introduce new errors.
Worked example
Draft: 'The principle was clear, its not acceptable to loose marks through careless spelling.' Corrections: 'principle' to 'principal' (the head or main one), 'its' to 'it's', 'loose' to 'lose'. The comma splice also needs a full stop or semicolon.
Rule of thumb
Read backwards, sentence by sentence, checking one feature at a time: spelling, then punctuation, then verbs.