Always spellcheck your work, especially after completing each draft iteration or editing pass. I don’t know about you, but my fingers have a mind of their own and don’t always type the words my brain had in mind. I’m notorious for typing “you” when I mean “your” or “the” when I mean “that” and a host of others. I’m sure you have your own set, unless you’re more thoughtful with your keyboarding skills. I’m a fast typist, with such goofs the price I pay for speed. These types of errors are extremely difficult to find in your own work because you’ll tend to see it as the expected word as opposed to what’s there, kind of like a rerun of that disconnect between your fingers and your brain that caused it in the first place. A good grammar checker should find any misused words. Test it out by deliberately using the wrong word, then seeing if it shows up.