Word.ws English Dictionary

i+1

i+1 adjective: containing only a single word unknown to the listener or reader.

Adjective

i+1 (not comparable)

  1. Containing only a single word unknown to the listener or reader.
    • Our SRS provides automatic i+1 sentence cards for optimal study.

Noun

i+1 (uncountable)

  1. The existence of only one word unknown to the reader or listener of a sentence.
    • When enough comprehensible input is provided, i+1 is present.

Origin of i+1

Ostensibly coined by Stephen Krashen in his Explorations in Language Acquisition and Use in 2003; but possibly earlier. Originally, referred to a subsequent word (the 1) added to an existing vocabulary of i words, i.e. the i+1th word learned by the learner.

Questions about i+1

What does i+1 mean?
I+1 means containing only a single word unknown to the listener or reader.
What part of speech is i+1?
I+1 can be an adjective or a noun.

Words near i+1 in the dictionary

  1. I've got news for you
  2. I've got your nose
  3. I've lost my keys
  4. I've never heard it called that before
  5. I'ven't
  6. i+1
  7. i-
  8. i-adjective
  9. i-adjectives
  10. i-banking
  11. I-bar

Source and license

Adapted from Wiktionary: i+1 (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated:

Cite this entry: “i+1.” Word.ws, https://word.ws/i%2B1. Based on Wiktionary, CC BY-SA 4.0.