After you file

My father informed me that either 2017 or 2018 he might have claimed me as an adult dependant before I moved out..if it was 2018..could that be the "if otherwise qualified" you stated above. ? Or would that have been an automatic rejection code from the IRS, if my SSN was on another tax return?. As I understand it..if I was claimed on another return and it turns out it was 2018.. then I would be exempt from receiving my stimulous..Sorry I am having so much difficulties with understanding this.