There, their, and they’re are probably my most common mistakes in writing; I don’t even think I ever know when to use the last they’re. I also mix up my i’s and e’s, which usually ends with me not spelling their correctly. Affect and effect are other homophones, and I don’t see the difference in either, in which case I only use the second one.
Another common error I use in my writing is my usage of semi colons. I know how to use them, but a lot of the time I use them too much and they usually turn into run on sentences. Commas, on the other hand, I sometimes don’t use enough. For example, when listing things (like red, green, and blue), I don’t feel the need to put a comma before the and, which I usually see added in my writing after it has been graded.
The link below is a website that basically tells you every homophone that’s out there, and there are many that I didn’t even know exist. When it comes down to it, writing is essential for a designer, from simply spelling the word right on a poster to sending professional emails to the client.
– Alan Cooper, (a.k.a Mr. Homophone)