This was my most in depth lesson on the Object Marker (을/를) and all of its uses. From the video description:
We learned how it's used with action verbs, how it can't be used with descriptive verbs, and I provided some common descriptive verbs it gets mistakenly used with by beginning learners. We also learned about not using it with verbs showing communication or giving, how it can be dropped in everyday conversations, how to use it with the verb 하다, several common contractions, and talked about the differences between transitive and intransitive verbs. Then we learned how to avoid repetition using multiple object markers, and how to use the object marker to indicate the location of movement (similar to the particle 에). Finally we learned some advanced language terms for the markers in Korean.