Ana's warm, blackboard-style grammar explanations — the biggest Spanish teaching channel.
Details
With around 1.6 million subscribers, this is the channel most beginners land on, and it deserves the reach: Ana explains one grammar point or vocabulary set per video, in English early on and increasingly in Mexican Spanish later. Uploads have slowed to roughly one every month or two, but the back catalogue is a complete beginner grammar course in itself. Best used as targeted explanation when something confuses you, not as a curriculum to work through in order.