This video by EnglishPage.info reviews the rules we have studied about the present progressive (also called the present continuous) and adds some new rules. For example, it explains that we sometimes use the present progressive to talk about the future:
"She is going to Paris next week."
In addition, we learn that with certain time expressions such as always and repeatedly, we sometimes use the present progressive instead of the habitual present:
"My friend is always interrupting me when I study."
(It is also correct to say, "My friend always interrupts me when I study.")