Proofreaders correct spelling, punctuation errors

Proofreaders spot and correct numbers and monetary

A proofreader is the person who strives to make text accurate and readable. Proofreading gives you a chance to make sure that no words are missing and that your spelling is correct. Proofreaders also check that capital letters and punctuation such as question marks, apostrophes, commas, and full stops are all in the right place, in addition to carefully checking document formats, spacing, type fonts, and font sizes.
Proofreaders train over many years to develop an eagle eye for detail, and a good proofreader can spot an extra space in a text or a single letter mistakenly inserted into a word in a different sized font, among many other errors. Even incorrectly-sized punctuation marks such as periods and/or commas won’t escape a seasoned and persnickety proofreader’s notice.
Proofreading is not an innate ability; it is an acquired skill. Most errors in written work are made unconsciously. A good proofreader reads any text more than twice, very carefully. Sometimes proofreaders read aloud in teams, for example, when proofreading legal documents. This is called a readthrough. Sometimes proofreaders read a retyped document against an original version of the document. This is called comparative proofreading. And sometimes proofreaders read a document blindly, that is, there is no other document to compare it to. This is called cold reading.
When reading a copy against an original a good idea is to read the lines from right to left. That way you can catch an extra word or letter that was mistakenly inserted. It’s also very important to pay special attention to numbers and monetary figures or you could end up with a real disaster.
Many people find it difficult to spot mistakes when reading text on a computer screen, therefore professional proofreaders read the final copy after printing it out on paper as well.