Comprehensible Input: A Practical Guide (With a Daily Routine)

Comprehensible input is language you can mostly understand — roughly 90–98% of the words are known, and context carries the rest. Understand the message, and your brain picks up the grammar and vocabulary on the way. That is the whole idea behind immersion-based learning, and it is what the input-based method optimizes for.

Where the idea comes from

Linguist Stephen Krashen's Input Hypothesis argues that we acquire language by understanding messages slightly beyond our current level — often written as i+1. Not drills, not conjugation tables: understood meaning. Two consequences follow directly:

• Too hard is wasted time. If you understand 50% of a video, you are decoding, not acquiring.
• Too easy is wasted time too. With zero unknown words there is nothing new to pick up.

The four principles that matter in practice

1. Understanding first. Look things up freely. Understanding a sentence today beats struggling with it for ten minutes.
2. Volume beats intensity. An hour a day of material you enjoy beats a heroic weekend you never repeat.
3. Interest is a difficulty setting. Content you care about is effectively easier, because motivation carries you through unknown words.
4. Review only what you actually met. Words you have seen in context stick; words from a random frequency list mostly do not.

How to tell if something is at your level

Read or watch two minutes and count roughly how many words you did not know:

• 0–2 unknown per 100 words — great for extensive reading and listening, fluency building.
• 3–10 unknown per 100 words — the sweet spot for intensive study with lookups.
• More than 10 — drop down a level, or use a transcript and read first, then listen.

A daily routine you can keep

This is about 45 minutes and works for Japanese, Chinese, English, Spanish — any language you are reading toward.

1. 10 min review. Clear your SRS vocabulary queue first, while you are fresh. Words come from what you read yesterday.
2. 20 min intensive input. One article, one YouTube segment, or one textbook passage in the reader. Tap unknown words, save the ones worth keeping — five to fifteen a day is plenty.
3. 15 min extensive input. Something easier and fun, with no lookups at all. This is where reading speed and listening comfort come from.

Do this five days a week and you have around 200 hours of contact per year, all of it at your level.

Doing this in InputDojo

The whole app is built around this loop, so you do not have to assemble it from five tools:

• Bring your own material. Paste a YouTube link, an article URL, subtitles, or photograph a textbook page — it becomes a lesson with tappable words in the interactive reader.
• Instant lookups in context. Tap any word for readings, meaning and grammar notes without leaving the text.
• SRS vocab review from your own reading. Saved words enter a spaced-repetition queue, so review reinforces the input you actually chose.
• Difficulty checks. The text level checker and YouTube difficulty checker tell you whether something is comprehensible before you commit an hour to it.
• Targeted lessons. Generate a lesson made of words and grammar you have not marked as known yet, so the next thing you read is i+1 by construction.

Common mistakes

• Watching without understanding. Background audio in a language you barely know is not input. Use transcripts until you can follow it.
• Hoarding vocabulary. Saving 60 words from one article guarantees you will quit the review queue. Cap it.
• Waiting to be "ready" to read. Graded material and a reader with lookups mean you can start in week one.
• Skipping output forever. Input builds the system; speaking and writing make it fast to retrieve. Add a little once you can follow simple conversations.

Start today

Pick one video or article you genuinely want to understand, run it through InputDojo, read it with lookups, and save ten words. That is a complete comprehensible input session — repeat it tomorrow.