Prefixes

When you are reading, you will come across unfamiliar words. It is often possible to guess the

meanings of these words if you understand the way words in English are generally formed.

prefix→ stem ←suffix

An English word can be divided into three parts: a prefix, a stem, and a suffix. Pre - means 'before'. A prefix, therefore, is what comes before the stem. Consider, as an example, the prefix de- (meaning 'reduce' or 'reverse') in a word like demagnetize (meaning 'to deprive of magnetism'). A suffix is what is attached to the end of the stem. Consider, as an example, the suffix -er (meaning 'someone who') in programmer ('a person who programs'). Suffixes change the word from one part of speech to another. For example, -ly added to the adjective quick gives the adverb quickly. Prefixes, on the other hand, usually change the meaning of the word. For example, un- changes a word to the negative. Unmagnetizable means 'not capable of being magnetized'. Let us now consider some prefixes, their usual meanings, and how they change the meanings of English words.

Verb PrefixMeaningExample

Em- put into empower

En- ‘ ‘ encourage

Dis- opposite/not disappear/dislike

Mis- wrongly mistake/ misunderstand

Over- too much overdo/overcook

Re- again replay/reuse

Un- reverse action unload/untie

Under- too little undercook

Adj.PrefixMeaningExample

Il- opposite/not illegal/illegible

Im- opposite/not impossible/immodest

In- opposite/not incorrect/insensitive

Inter- between international

Ir- opposite/not irrelevant/irresponsible

Non- not non-smoker/non-alcoholic

Over- too much overweight

Un- opposite unfair/unkind

Under- too little underweight

Negative prefixes un- unmagnetized in- incomplete im- impossible il- illegal ir - irregular, irrelevant non- not connected with non-programmable mis- misdirect mal- bad, wrong malfunction dis- opposite feeling disagree opposite action disconnect anti- against antiglare de- reduce, reverse demagnetize, decode under- too little underestimate	Positive prefixes re- do again reorganize over- too much overloaded	Prefixes of location: inter- between, among interface, interactive super- over supersonic trans- across transmit, transfer ex- out exclude, extrinsic extra- beyond extraordinary sub- under subschema infra- below infra-red peri- around peripheral inter = inside (intercontinental)	Prefixes of time and order: ante- antecedent pre before prefix prime- first primary, primitive post- after postdated retro- backward retroactive
Prefixes of size: semi- half, partly semisphere equi- equal equidistant mini- small minicomputer micro- very small microcomputer macro- macroeconomics megalarge, great megabyte pre = before (pre arrangement) pro = in favour (pro-life) pro- before, in advance program,	Other Prefixes: auto- self automatic co- co-ordinate con- together, with connect	Prefixes of numbers: semi- half semicircle mono- one monochromatic bi- two binary tri- three triangle quad- four quadruple penta- five pentagon hex- six hexadecimal sept(em)- seven September oct- eight octal dec- ten decimal multi- many multiplexor