I strongly recommend that anyone learning a language should develop a practice of immersion. What follows is a list of commandments friendly advice for effective immersion that worked for me. I originally smuggled them out of research on linguistics, such as Krashen's input hypothesis, and on expertise, like deliberate practice.
(I also recommend spaced repetition, mnemonics, and any other force multipliers you can scrounge together)
#1. Rack up hours, not years
The most important rule of immersion is that it's about the hours. You need to give your brain as much input as possible, so that it can make sense of anything. As a very rough starting point, aim for at least 8 hours a day. If that sounds daunting, keep reading (tl;dr: don't pay attention). Or, if you can do more, then by all means!
The underlying insight here is to optimize for what are called i+1 moments. Each one is a tiny, incremental growth in your language ability. The i refers to the sum total of all that you know about the language. Context clues, like body language, help you make this +1 jump. (A software engineer would write it as i += 1). Think of it as connecting two dots… or neurons. Unfortunately you can't select just those moments, at least not with current technology. So the best you can do is generate as many opportunities as you can, by immersing as many hours as possible.
I promise you this works. Your brain will magically start picking up on phrases it hears frequently. Because it's frequent, it must be important, so it better keep tabs on it. The feeling I get when this happens is "I hear this everywhere now, why did it take so long to notice it?" Repeat until fluent. (Really. The input hypothesis says output will come naturally, so practicing it is not very important. With a name like "input hypothesis" it totally would say that though, wouldn't it)
Try to avoid skipping days, because that resets your frequency counters. It limits the effectiveness of immersion you've already done, so it's a double whammy.
We often talk about the number of "years" we've been studying as a sort of shorthand. But you can probably think of some examples where years did not correlate well with ability. I bet you'd find a much stronger correlation between hours and ability.
#2. For native speakers, by native speakers
You definitely don't want to learn Spanish from Arrested Development. Learn the real thing instead.
One consequence of this rule is avoiding classrooms. Most will have you spend lots of time listening to other beginners speak. Same with language textbooks, which are not for native speakers. (But if you want to pick up, say, a geology textbook in your target language… that rocks!)
I give you my full permission to listen to whatever the heck you want, as long as it fulfills this native-speaker rule. Anime, children's shows, reality TV, trendy TikTok videos. Advertisements make me irrationally angry. But if that's what's working for you, I will cheer you on. As your ability grows, so too will your tastes naturally change.
When I started immersing Japanese, I listened to Yomiuri News Podcast exclusively, on repeat. That was… fine? The content didn't matter much since I didn't know anything. (Embarrassing proof: around this time I learned that "sayonara" was not actually Italian). I was just getting used to the sounds of the language. But I should have started with, like, Dragon Ball, to keep it a little more interesting.
The linguistic term for this is "affective filter". In short: having fun helps you learn more.
#3. Make it automatic
Every manual intervention implicitly offers the choice to stop immersing. That just won't do. The default should be relentless, continuous immersion.
Take a page from the sort of people who get big bonuses for "boosting engagement metrics".
Once a video ends, the next one should start automatically. You can achieve this by building up a queue at the start of your session. (Though if you can automate that too, even better!)
If you have to manually download videos, see if you can find a way to always be downloading the next few automatically, so you always have a healthy buffer.
This advice also applies to audio track selection. If your video has English and French, find a way to automatically select lingua franca every time. (That's a pretty good joke). Otherwise you have to interrupt whatever you're doing, which is death by a thousand cuts.
Make it as easy as possible to start immersing. The gold standard would be zero effort. As in, always be immersing. Paraphrasing AJATT, "the best way to learn a language is to go to the country, turn the TV on, and leave it on for two years". That might not be practical (as described below in Turn down the volume). So instead, make it as close to a single button press as you can.
Immersion and willpower do not mix well.
#4. Skip intros and credits
Netflix has a "skip credits" feature. This stroke of genius has saved countless centuries of human life. On the other hand, it is nice that I always have "dokkan dokkan, tsuiteru" in my back pocket in case of karaoke emergency.
Hearing the same song every 20 minutes has a couple problems. It displaces the time you could have spent listening to more interesting, useful (i+1) content. But even moreso, I personally find it to be quite grating. Enough that it presents an off-ramp to immersion, which is the recurring villain here.
If this skip-credits feature is not available natively in your media player, I encourage you to find a way to hack it. I wrote my own media player software, for which I manually annotate skip starts and ends for each video. That may sound like a lot of work, and it is. But the entirety of Hikaru no Go is about 29 hours, which is only a few days of immersion when racking up hours. Since I keep coming back to it, setting up skips was worth doing.
As a last resort, you could destructively trim the beginning and end of each video. It's a little regrettable, but it will work in any media player. Stash away the originals I guess.
#5. Turn down the volume instead of pausing
This one is hard. But in the spirit of make it automatic, pausing sets a trap for future-you. You will eventually need to summon the willpower to unpause.
Keeping the immersion flowing also signals to those around you that this is important to you. And hey, at least you turned it down. You're meeting them halfway. How dare they, if I may.
I get that there are obviously circumstances where immersing would lead to undesirable outcomes. If you're giving a presentation to the entire company. If you're in a heated argument with your partner. (Unless the argument is about how you don't take learning their language seriously. Checkmate!)
In such situations, consider muting. It's easier to unmute than it is to unpause, especially if your brain treats a muted, playing video as an "I left that thing unsettled" annoyance.
The real intent of this advice is that pausing should be the exception, rather than the default.
#6. Do not pay attention
If it feels like work, then you're doing too much. And that feeling of expending effort will give you a great reason to not continue immersing tomorrow.
Instead, let the audio wash over you. Don't actively listen, and don't make an effort to understand. And definitely do not translate. You'd just be reinforcing bad habits. (This is a consequence of … by native speakers, which you are not). It's just entering your ears. It's the easiest thing that could possibly work, and yet, that is enough to count towards your hours.
Let me proactively address a complaint you might already be forming here. There is absolutely value in studying video. This is when you give it your complete focus, read subtitles, mimic what people are saying, rewind liberally, pause and look up vocabulary, try to glean more meaning from context and body language, sentence mine into Anki flash cards, etc etc. This is all great! I do it too. I just call that something else: purposeful practice. These commandments are about the entirely passive process of immersion.
Like what babies do to acquire their first language. No baby ever has "studied" language.
#7. Don't watch video. Listen to podcasts
You know, watching all those people going around, doing people stuff makes it too easy to accidentally break the don't pay attention rule.
Wait!, I hear you say. I'm learning Yoruba but I'm not a fan of This Nigerian Life. Or any podcast!
That's okay, because did you know that embedded in every video is a secret podcast? This is not literally true (see the first 35 minutes of WALL-E), but it rounds to true.
Put in (on?) your headphones. Press play on the video, then put your phone in your pocket. There's your podcast. Then go do whatever it is you do. Listen to people going around, doing people stuff. In your target language.
As of this writing, iOS lets you unpause the video from the lock screen, which plays only the audio. This extends your battery life since you aren't burning resources to decode or render the video stream.
If you want to actively use your phone, you can activate the picture-in-picture feature, then push the floating video window offscreen. It'll keep playing the audio.
#8. Spend money, in as much as it helps
I spent probably $5 on a second-hand Japanese DVD of The Matrix. It absolutely should have melted with the sum wattage of laser it's been hit with. Superb value for money.
eBay is a treasure. So are foreign editions of Amazon. If Japanese is your jam, Book Off could be a third place for you.
That said, if what you want is free, take full advantage of that! Between YouTube and Twitch, there's probably a billion hours of Danish speakers playing Elden Ring.
And do not waste money for content that doesn't speak directly to your soul, even if you feel like you "need" to. There seems to be a huge wing of modern Hong Kong cinema that is just about cops and drug kingpins, and sometimes even cop kingpins. Hard pass for me.
#9. No translated subtitles
"The path of least resistance" governs everything from physics to society. If you're watching a movie in Arabic and there are English subtitles onscreen, your brain is going to take the shortcut you presented it. You might as well switch the audio track too for how much you'll get out of it. That is a harsh sentiment, but I really don't want you to make this easy mistake.
This is your official welcome into the "dubs not subs" crew.
The only language I want to see in your Arabic movie subtitles is, of course, Arabic. Still, you should be listening, not reading. But, matching subtitles won't actively harm your immersion. Since it's for native speakers, by native speakers.
You might say, well, the movie was originally in English then dubbed into Arabic, so actually, "no translated subtitles" would forbid Arabic and permit English. Sure. You're very clever.
#10. Forgive yourself
Some days you won't be able to immerse at all. Maybe you've got your bar exam this week and you really just need to cram allll the justice into your head. Maybe you can't bring yourself to get out of bed today, and the only thing that helps is scrolling through cat pictures.
I've been there, I know. Do what you gotta do. Maslow's hierarchy of needs is not opt-in. Especially for the many of us who get to treat language learning as a "self-actualization" luxury.
If and when you're ready to come back, don't beat yourself up for something so silly as "lost time". Press unpause and keep ticking up those hours.