In past times tense, the verb “do” modifications to “did” for all subjects. However, “does” stays unchanged inside the 3rd-person singular present tense. Here are a few illustrations: These helping verbs let to the sign of actions or states of becoming without the repetition of the key verb. From https://advicebookmarks.com/story28043387/5-simple-statements-about-does-proleviate-help-with-shoulder-pain-explained