Fortis (from Latin fortis "strong") and lenis (from Latin lenis "weak") are linguistics terms.

In a wide sense, they refer to the opposition of consonants such as p, t vs. b, d. In a narrow sense, fortis refer to consonants such as p, t pronounced with articulatory strength and lenis to consonants such as b, d pronounced without articulatory strength.

History and use of the terms

These terms have already been used in 19th century German Linguistics, in order to describe languages such as southern German where consonants such as b, d are voiceless but nonetheless different from p, t.

In current linguistics, they occur only marginally.

Opposition of p, t versus b, d

Normally, the opposition of consonants such as p, t vs. b, d is described in terms of voiceless consonants vs. voiced consonants. There are languages where this is indeed the only feature that distinguishes them (e.g. French: IPA [p, t] vs. [b, d]). In many languages, however, the phonetic voice is only one of several features that constitutes this opposition (e.g. English: IPA [pʰ, tʰ] vs. [b, d]). There are even languages where the phonetic voice is not a distinctive feature of these pairs at all (e.g. southern German: IPA [pʰ, tʰ] vs. [b̥, d̥]).

The terms fortis and lenis (in the wide sense) apply to this opposition regardless of whether it's only an opposition of voice or not. Therefore, it allows to speak in the same terms of French, English, or southern German consonants.

Consequently, they refer to a bundle of articulatory features which have different distributions in different languages. Not all of them need to be present in a particular language:

• voice (voiceless vs. voiced)
• length
• aspiration
• articulatory force

Articulatory force

The articulatory force is the feature that distinguishes fortis and lenis in the narrow sense: In the articulation of the fortis, more muscular energy is used, so they have a bigger articulatory force.

Even though this feature may be intuitive, it cannot be measured directly, although measuring acoustic energy may provide an approximation.

External links

• fortis and lenis (http://www.hi.is/~peturk/KENNSLA/02/TOP/fortlen.html)