Three common mistakes with the use of capital letters involve proper nouns, titles, and seasons.
Proper Nouns
Proper Nouns are the names given to common nouns, as in Michael is my son. The word son is not proper in this case, but Michael is. Unless a person only calls him Son in place of Michael. Then it becomes a proper noun.
Any mom is common. My mom is still common. But in, “Mom, please give me a ride to school,” the person named Mom and maybe not Sally is a Proper Noun. Likewise, Grandma is capitalized when one is speaking to her specifically, using her role in place of her given name. or combining Grandma with her name, “Grandma Betty is napping now, so be quiet.”
Titles
When providing a title for a book, article, or place, use capital letters on all words, except small articles (and, by, for, a, or), The Institute of Correctional Research.
Seasons
Never use capitals on the four seasons, winter, summer, fall or autumn, and spring, unless it is the first word in a sentence, or part of a title, University of Minnesota Fall Semester Schedule. The seasons are normally just a common noun. Oddly, the names of the week and months of the year are considered Proper Nouns; therefore, they still need to be capitalized.