A privative, named from Latin to deprive, is a particle that negates or inverts the value of the stem of the word. In Indo-European languages, many privatives are prefixes, but they can also be suffixes, or more independent elements.

Privative prefixes

In English there are three primary privative prefixes, all cognate from Proto-Indo-European: These all stem from a PIE syllabic nasal privative *n̥-, the zero ablaut grade of the negation *ne, i.e. "n" used as a vowel, as in some English pronunciations of "button". This is the source of the 'n' in 'an-' privative prefixed nouns deriving from the Greek, which had both. For this reason, it appears as an- before vowel, e.g. anorexia, anesthesia. The same prefix appears in Sanskrit, also as a- अ-, an- अन्- (, -n- infix). In Slavic languages the privative is nie- and u-, e.g. nieboga, ubogi. In North Germanic languages, the -n- has disappeared and Old Norse has ú- (e.g. ú-dáins-akr), which became u- in Danish and Norwegian, o- in Swedish, and ó- in Icelandic. Privative prefixes are not feature of Indo-European languages only, but also exist in languages belonging to other families, such as (Semitic).

Confusion of privative and non-privative in English

Many words introduced into the English from the Latin start with the prefix in-. While often, it is a privative, it is not always so. Even if it is a privative, the meaning may be unclear to those who are not familiar with the word. The following three examples illustrate that: The prefix in- arises from the Latin for "in, inside, within" and inflammable derives from the Latin root inflammāre meaning "able to be set alight, able to kindle a flame". Since at least the 1920s, there have been calls to stop using inflammable and substitute it exclusively with flammable to avoid the confusion that occurs even by native English-speakers.

Privative suffixes

Some languages have privative suffixes; -less is an example in English. Further examples are -t(a)lan or -t(e)len in Hungarian or -ton/-tön in Finnish (non-IE languages).