Seek the Opinion of Another Person.
Although it may seem easy at first, there are actually a significant number of ways that writing can go catastrophically wrong. If the standards of spelling and grammar aren’t followed, an error-prone coder could wind up with something like this if they don’t pay attention to detail. The word “vowels” is spelled correctly. Therefore the vast majority of spellcheckers would have overlooked the error.
It cannot be stated any more plainly than that. If you are concerned about something similar to this, you should have a buddy look it over for you. Even when we’re creating something as straightforward as a computer program, we put on the artistic equivalent of blinders. Before someone else brings them to our attention, we are unable to recognize our own shortcomings.