The aim of this study was to determine whether a half-hour intervention could improve children's use of apostrophes or capitals, and whether this use was related to morphological awareness. Participants were 55 children in Grades 3 to 4 (24 males; M = 9.56 years, SD = 6.29). Results demonstrated that the intervention group significantly improved their use of plural possessives (e.g., trees'), but not singular possessives (e.g., tree's) or plurals (e.g., trees). The control group did not improve on any word type. Intervention was not successful for children learning to distinguish when to use or avoid capital letters (e.g., Turkey vs. turkey) with no improvement from either the intervention or control group. A follow-up pilot study of 19 children in Grades 5-6 (13 males; M = 11.44 years, SD = 9.04) demonstrated greater improvement, suggesting that a certain knowledge level is necessary for successful intervention. A second follow-up study of 26 adults (7 males; M = 30.54 years, SD = 15.51) indicated that while spellers did use capitals proficiently by adulthood, their use of apostrophes was far from perfect. Contrary to the hypothesis, no systematic patterns emerged between participants' morphological awareness and their ability to use apostrophes and capitals. Implications for future interventions and education are discussed.