John Larrysson's Column: A Pair of French Prefixes Commonly Used in English: In- and In-

There are two in- prefixes used in English. Unlike the more common un- prefix, these two are of Latin/French origin. The first in- prefix means not and comes in several forms: in-, im-, il-, ir- (by changing the N to match the following consonant). Examples include: indirect, impossible, illogical and irregular, meaning not direct, not possible, not logical and not regular.

Also this prefix rarely appears spelt en- as in enemy. Sometimes the not form of the word survives in English and its original word does not. The word enemy comes from the Latin in- (meaning not) + amicus (meaning friend).

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The second in- prefix means in, as well as the related meanings to enter in, into, on or go on. As with the first in- prefix, it also comes in the forms  in- im-, il-, ir- and occasionally en- . Examples include: incorporate, import, illuminate and irradiate. [These mean to include a part into a whole (have a business become a corporation), bring goods into a country, shine light on a thing, expose a thing to radiation.] Also this prefix rarely appears spelt en- as in enlighten. (Meaning to metaphorically bring a person into the light of knowledge.)

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The two in- prefixes can be confused. The word inflammable means that a thing can be on fire and uses the second in- prefix, not the first. (The 3 most dangerous words in English) Another risky word is invaluable which uses the second in- prefix. For example, "Members of the public will have the rare opportunity to take a closer look at national-treasure-grade terracotta warriors and other invaluable relics from the Qin dynasty in this not-to-be-missed exhibition" (HK government press release June 13, 2012). The word invaluable does not mean not-valuable, but that it is so valuable, that no price or value can be put on it. (Meaning that it is priceless, not worthless.) To inculpate a person is to accuse them of a crime, but if they are inculpable it means that they are not culpable, or free from blame. There is some confusion between these two prefixes. 

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There are many words that use in- instead of un- to show the negative. They are typically words of French/Latin origin. The use of the in- prefix meaning not can be confused with the second different, but identical prefix in- meaning in. Knowing that these are the patterns should help you learning and understanding words with these prefixes. 

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Related articles: The Prefix Un-

by John Larrysson [email protected]

A native English speaker who has been teaching practical English in Hong Kong for over two decades.

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