In this age of flipped classrooms and MOOCs, there's no shortage of online video lessons for learners of English. The problem is sorting out the wheat from the chaff (and there's a lot of chaff!) One of my favourites is Espresso English, which I reviewed a few months ago, and, of course, there's my own (much more modest) Learn English With Photos collection. However, engVid is probably the 'market leader' when it comes to free English video lessons, with well over 500 video lessons by eight experienced native-speaker teachers, and more than 10 million users (according to their site blurb). New classes are added three times a week, covering grammar, vocabulary, pronunciation, TOEFL, and more. There's also a page with downloadable and printable reference (Grammar Mistakes, Job Interview Questions, etc.). Here's a sample lesson.
As you can see, the videos are professionally produced even there's nothing particularly innovative about them - it's basically just 'chalk and talk'. Still, the sheer number of lessons available make this an invaluable resource for learners who want to improve their passive skills. For a more detailed review, see Why engVid is an Amazing Resource for English Language Learners from EdTechReview.