Guide • Input
Comprehensible input for Japanese: the 80 percent rule
I tried to power through anime and news. I mostly stared at subtitles and learned nothing. When I stayed with material I could mostly understand, things finally moved.
Input research says you learn when you understand most of what you hear. The sweet spot is not perfect, just enough.
TL;DR: Stay around 80 to 90 percent comprehension, then mine one useful phrase.
What to do today: Pick a 60 second clip with a transcript. Listen once, read once, listen again.
Why the 80 percent rule works
Comprehensible input is the idea that your brain learns from messages it can mostly understand. If you only catch half the words, you guess too much and the input does not stick.
Research on vocabulary coverage suggests you need a high percentage of known words for good understanding. That is why easy material feels boring but works. It is also why the jump to native content feels brutal.
The 12 minute input loop
- Pick a short clip with a transcript. NHK Easy, a short podcast, or train announcements.
- Listen for gist. No pausing, no dictionary.
- Read the transcript. Mark one or two unknown words.
- Listen again. Shadow one sentence out loud.
- Use one phrase. Say it today or run a short Scenario drill.
Example: train announcements
These three lines show up on the Yamanote line almost every day. They are short, clear, and easy to repeat.
Next is Shinjuku.
tsugi wa shinjuku desu. 次は新宿です。
A short announcement line that is easy to shadow.
The doors will close.
doa ga shimarimasu. ドアが閉まります。
You will hear this right before departure.
The exit is on the left.
deguchi wa hidari desu. 出口は左です。
Simple and useful even outside the train.
Audio: Train announcement practice clip
Full transcript (JP + EN)
Japanese
まもなく、山手線内回りの電車が、1番線にまいります。
危ないですから、黄色い線の内側までお下がりください。
次は新宿です。
ドアが閉まります。
駆け込み乗車はおやめください。
出口は左です。
English
Soon, the Yamanote Line inner loop train will arrive at platform 1.
For your safety, please stand back behind the yellow line.
Next is Shinjuku.
The doors are closing.
Please do not rush onto the train.
The exit is on the left.
What you are supposed to get from the clip
The point is not to memorize every word. The point is to understand the message without pausing. If you can catch the station name and the action, you are in the right zone.
- Listen once for gist. Can you tell if it is arrival, departure, or safety?
- Listen again and track one line. Pick “次は新宿です” and follow it end to end.
- Shadow one sentence. Say it out loud right after the audio.
- Write one takeaway. For me, it was “ドアが閉まります” for when the doors close.
If you miss most of it, the clip is too hard. Use a shorter clip or read the transcript once, then listen again. The 80 percent rule means you can follow most of it without guessing every second.
How to apply this in daily life
- Stations: Listen for the station name and one action line.
- Stores: Catch a repeated line like “袋はいりますか” and use it the same day.
- Clinics: Focus on one instruction line and repeat it back to yourself.
- At home: Use 60 second clips with transcripts and stay in the 80 percent zone.
The takeaway is simple. You do not need hard content. You need understandable content, one clear phrase, and a small repeatable loop.
Related guides to practise with
Sources
If you want short input you can reuse
TabiTalk is built around short scenarios you can hear and repeat before you need them. You can try it on iOS or Android.