---
title: "i+1 — what it means · NoaLingua"
description: "i+1 describes material with exactly one unknown element beyond your level. Why it is a useful direction rather than a target you can measure."
url: "https://noalingua.com/glossary/i-plus-1/"
language: "en"
modified: "2026-08-17"
license: "CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/"
---
Glossary

# i+1 — the NoaLingua glossary

i+1 describes material containing exactly one unknown element beyond your current level — the theoretical ideal for acquisition.

The notation comes from the same input hypothesis as comprehensible input: "i" is your current competence, and "+1" is the single step beyond it.

Taken literally it is unattainable — no real sentence contains precisely one new thing. Taken as a heuristic it is useful: a sentence with one unknown word is worth mining, a sentence with six is worth skipping until later.

In NoaLingua Marking unknown words on a page with Alt+Shift+W is the practical version of this test: you can see at a glance whether an article is one-new-word-per-sentence or five, before committing to it.

## Related terms

[Comprehensible input Comprehensible input is language you can mostly understand but not entirely — the level at which exposure teaches you something new.](https://noalingua.com/glossary/comprehensible-input/)[Sentence mining Sentence mining is collecting sentences you encounter in real material and turning them into review cards, rather than studying isolated word lists.](https://noalingua.com/glossary/sentence-mining/)

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