Proofreading 40000 words can be a daunting task. It really depends on the type of text, the experience of the proofreader, and the time they have to dedicate to the project. Generally, it will take an experienced proofreader several hours to proofread 40000 words. For example, around 8 - 10 hours for a professional proofreader with a good eye for detail. That said, it's wise to factor in a bit of extra time for more complex texts. Ideally, you should start proofreading in advance to ensure that your text is error-free before the deadline.
If you are working on a tight schedule, then it may help to split the proofreading process into separate stages. This way, you can make faster progress by proofreading a certain number of words at a time. For example, you could proofread a few thousand words at once, take a break and then come back to review the results.
Ultimately, if you want to proofread 40000 words in the quickest way possible, it's best to hire a professional proofreader who can take care of it in the most efficient manner.
