I misspelled ‘not’ and mistakenly wrote ‘now’ instead. I have already submitted my common app to multiple colleges. What should I do?
Part of my essay:
The biggest lesson that I’ve learned is the importance of hard work, patience and determination in tackling just about any difficulty. The real question being when and now how!
Nothing.If every college autorejected all applicants with a small typo in their apps, they would be unable to fill their class.
But there’s some lesson here. I can’t believe how many kids are noticing spelling errors after submitting. Then, fretting on a college forum.
I agree a reader will suspect a typo and keep reading. But I do wish kids put more care into proofreading.
DH and I don’t have any employees, but occasionally we will receive resumes. I always look at them out of curiosity. It is surprising how many times there are typos or grammatical errors in the resumes or cover letters. Structural engineers need to pay particularly close attention to details, so it’s a little distressing that people looking for jobs would make such mistakes. 
As @lookingforward mentioned, proofread, proofread, proofread, and then ask someone else to check your work, also.
Oh, there are many adults who can benefit from more proofreading.
And while I agree to triple check, and have someone else proofread, let’s also be fair and not beat on the OP. Even when you proof, get someone else to proof, use spellcheck, grammarcheck, backup spellcheck, there’s invariably one that everyone/thing missed. It will happen again in college papers, in professional presentations, etc. Avoid it as much as possible, be suitably embarrassed when it happens (which it will), and then move on.
Before my kids pressed send we argued with them to let us proof read their applications. We found small errors on both. In the future when submitting something important, get another pair of eyes on it.
@MaineLonghorn. I had to laugh. It’s like when we interview employees and they tell us in their resume they give such great attention to detail but misspell detail… Lol…
It is always important to double check your content before hitting the submit button so that you see the unnecessary error.
I agree with all of the above posters- and will take a slightly different tack for the OP:
When I submitted my PhD thesis I had proof-read it multiple times. Had 2 colleagues proof read it. Had paid a professional proof reader to read & correct it.
I actually refer to my thesis occasionally (turns out there’s some useful stuff in there!). Almost every time I do I find a typo.
tl;dr: AdComms can tell the difference between a one-off typo and something that is poorly written or badly proofed. Stop second guessing yourself: 100% that typo is not going to affect your admission decision.
While it’s too late now, it’s a good idea to try “reading backwards”. I usually do this sentence by sentence, starting from the end. It forces you to focus a bit more on each word and see if each sentence on its own makes enough sense.
As others have said though, I doubt this will really affect anything. Past the 100th essay they’re probably skimming anyway.
What you should do is stop re-reading essays for applications that have been submitted. Don’t make a difficult process more stressful but second guessing every choice you have made and nit-picking every essay you wrote. College admissions officers do not expect perfection from HS seniors. Any time you feel an urge to look at a submitted application get out of the house and spend time with your friends and family.