Does shadowing actually help learn a language?

Yes, shadowing helps, but only with specific things: pronunciation, rhythm, your ear for fast speech, and the speed of your own output. It won't teach you new words or grammar on its own, so it works as a sharpening tool on material you already understand, not as your whole method.

Shadowing means playing native audio and repeating it out loud almost at the same time, trailing a half-second behind like an echo. What that trains is the part a quiet flashcard can't reach. Your mouth learns the real melody and timing of the language, and your ear learns to catch where one word ends and the next starts, which is exactly the skill that fails you when locals talk fast. Say enough whole phrases at native pace and "I know this" turns into "I can say this without freezing".

What it doesn't do is hand you meaning. You can shadow a sentence perfectly and not know what it means, so it pairs with learning the words, it doesn't replace it. Learners who add a few minutes of daily shadowing usually notice they sound more natural and stall less. Just don't expect it to carry the vocabulary load, and mind where shadowing falls short.