--- title: Prefixes: un-, dis-, mis-, re-, pre-, in-, im-, il-, ir- — a lesson of Mova's school · trees and pragmatics description: «Prefixes: un-, dis-, mis-, re-, pre-, in-, im-, il-, ir-», a lesson of the english course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: A prefix is a few letters added to the front of a word that change its meaning: happy, unhappy; do, redo; view, p --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [English](https://md.mova.elamur.ai/free/en/corpora/school/english/) / Prefixes: un-, dis-, mis-, re-, pre-,… # Prefixes: un-, dis-, mis-, re-, pre-, in-, im-, il-, ir- Lesson 12 of the english course of Mova's primary school: 20 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: [the lesson at school](https://md.mova.elamur.ai/free/en/school-run/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/0/) — A prefix is a few letters added to the front of a word that change its meaning: happy, unhappy; do, redo; view, preview. - [1](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/1/) — The best news for spellers: a prefix never changes the spelling of the root word. - [2](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/2/) — Write the prefix, then the whole word, letter for letter. - [3](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/3/) — That one rule explains the famous double letters. dis + appear = disappear (one s, because «appear» has none), but dis + satisfied = dissatisfied (two s's). mis + spell = misspell, with both s's. il + legal = illegal, ir + regular = irregular, im + mature = immature. - [4](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/4/) — The doubles are not mistakes; they are the end of the prefix meeting the start of the word. - [5](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/5/) — Several prefixes mean «not», and the first letter of the root often picks which: im- before m or p (impossible, immature), il- before l (illegal, illogical), ir- before r (irregular, irresponsible), in- for many others (incorrect, invisible), and un- for very many common words (unhappy, unkind). - [6](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/6/) — So «unpossible» is wrong; it is «impossible». - [7](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/7/) — Others carry their own meaning: re- again (redo, rewrite), mis- wrongly (misread, misspell), dis- not or the opposite (disagree, disrespect), pre- before (preview, prehistoric), sub- under (submarine, subheading), auto- self (autobiography, automatic), bi- two (bicycle), tri- three (tricycle). - [9](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/9/) — Prefixes let you guess new words. - [12](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/12/) — A prefix is added to the start of a word and changes its meaning. - [13](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/13/) — Adding a prefix never changes the spelling of the root word: dis + appear = disappear; mis + spell = misspell. - [14](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/14/) — Prefixes meaning «not» include un-, in-, im-, il- and ir-. - [15](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/15/) — im- is used before many words starting with m or p: impossible, immature, impatient. - [16](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/16/) — il- is used before l (illegal, illogical) and ir- before r (irregular, irresponsible), so these words have double letters. - [17](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/17/) — re- means again: redo, rewrite, replay. - [18](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/18/) — mis- means wrongly: misread, misspell, misbehave. - [19](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/19/) — dis- means not or the opposite: disagree, dislike, disrespect; the slang «diss» comes from «disrespect». - [20](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/20/) — pre- means before (preview, prehistoric); sub- means under (submarine, subway). - [21](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/21/) — auto- means self (autobiography, automatic); bi- means two (bicycle); tri- means three (tricycle). - [24](https://md.mova.elamur.ai/free/en/corpora/school/english/12-prefixes-un-dis-mis-re-pre-in-im-il-ir/24/) — Slang in this lesson: «fixin' to» means «about to» in the US South; «love» is a friendly way to address someone in much of Britain. - ← previous: [Homophones and near-homophones](https://md.mova.elamur.ai/free/en/corpora/school/english/11-homophones-and-near-homophones/) - next →: [Words to know, Years 3–4 (the statutory list, by idea)](https://md.mova.elamur.ai/free/en/corpora/school/english/13-words-to-know-years-3-4/) - ↑ back to [English](https://md.mova.elamur.ai/free/en/corpora/school/english/)