Importing Lessons Question. Dubbed Movie Scene Clips from Youtube?

Hi there, i recently discovered some american movies scenes/clips dubbed in Russian on Youtube. I would like to take these short scenes and create a script and use them as a lesson. Is this permitted? also i have found that sometimes people upload clips of dubbed stand up comedy specials on YouTube as well. what are the limitations of using stuff that’s posted on YouTube? i figure as long as the stuff is allowed on YouTube and there’s a script that goes with the audio file is this okay?