The latest XKCD comic is titled Intervocalic Fortition. The latest Explain XKCD says:

The linguistic processes of lenition ("weakening") and fortition ("strengthening") refer to a sound becoming, respectively, either more or less vowel-like. Intervocalic means "between two vowels." An unvoiced consonant like f in between two vowels (which are almost always voiced) is more noticeable and takes more effort to pronounce than the voiced version v of the same sound in that position, so a change from v to f in this context would be an example of fortition.

Can anyone give me some examples of lenition and fortition used in a more conventional way to help me better understand these concepts?

  • Lenition: write -> writer (the 't' gets much weaker in 'writer') Fortition: the -> duh as in 'Duh Bears' in a Chicago accent. – Mitch Jun 24 '16 at 13:33
  • Sorry, Amy. My answer was way off. I posted about vowels, not consonants. Please unaccept my answer. – miltonaut Jun 24 '16 at 23:41
  • @miltonaut: You can also edit your answer, if you think you have the time. – sumelic Jun 26 '16 at 2:29

In Stampean Natural Phonology, which mostly agrees with the traditional use of these terms in phonology, a lenition is a phonetic change functioning to make speech easier to articulate, and a fortition is a phonetic change functioning to make speech easier to perceive.

The insertion of a vowel homorganic to the following glide in the [bj] cluster, for emphasis and extra expressiveness in the pronunciation "bEE-eautiful!" is a typical fortition. The flapping of /t/ in the same word, which makes the sound sonorant, to agree with the surrounding vowels, is a typical lenition.

Dissimilations are generally fortitive, while assimilations are generally lenitive. Fortitions are often stylistic and under conscious control, while many assimilations are permanent aspects of a language's phonological system, and go unnoticed.


Lenition and fortition are names of sound changes usually occurring over many hundreds of years and show up when comparing words from different dialects or different eras (Irish is one of the few language where there are many context changes that are lenition). So there may not be many good examples residing entirely in modern English.

The word 'maternal', created directly from the Latin word 'mater', English for 'mother', has a 't' pronounced as strongly and aspirated as possible. That 't' is a vestige of the more ancient Proto-Indo-European, from which both Latin and English come.

Then 'mother', the 't' has changed, weakened, lenited, to a fricative.

Then the French version of 'mother', 'mère', has lost the original 't' entirely, it has weakened away to nothing a all.

Going in the other direction, strengthening or fortition, the 'th' in 'the' is soft or weak. But in some dialects or in young kids just learning, 'the' is pronounced 'duh', as in 'Duh Bears'. That is, going from 'the' to 'duh' is the process of fortition.

Lenition is more common among world languages than fortition (the 'lazy speaking' theory of the cause of sound change). It follows a number of paths of weakening, usually from

unvoiced stop to voiced stop to affricate to fricative to h/glottal stop to nothing


stop to palatalized consonant to affricate and so on.

or some similar weakening trend.

For English speakers in the US and UK, the culturally most obvious expression of lenition is not in English itself but in the comparison of Latin, Spanish, and French. A 'k' sound in Latin became (almost always) at the beginning of a word a hard 'g', cattus -> gato. In French, cattus -> *kyat -> tchat (Old French) -> chat (Fr) pronounced as 'shah'. Lots of Spansish words that start with 'g' came from a Latin 'k' sound (written as 'c') and lots of French words starting with 'ch' came from the same place.

Don't get me started on Irish. What a mess.

  • Could you tell me where you got the information for this so I can have a read through the source material? – user182372 Jun 26 '16 at 10:01
  • I have links in my answer. There are many more examples there. You probably also want to look at phonological rules and distinctive features to get some explanation of the scientific terminology. – Mitch Jun 26 '16 at 12:56
  • For a quick glance at a phonological system look at the consonants and their features in English Also you may get better exposition in an intro linguistics text than from the haphazard pages in wikipedia. – Mitch Jun 26 '16 at 13:16

An example of "lenition" which weaken a consonant sound into a vowel-like sound are words like:


In the former word the consonant is stressed and hence is pronounces as 'H-erb'. In the word the consonant is softened to the point of non-existence so the word is instead 'erb' with a marginally softer vowel sound.

On the other hand, sometimes the consonant sound will actually make it harsher and less 'vowel-like'. This is slightly more difficult to objectively gauge since the condition of transitioning from 'consonant sound' to 'vowel sound' may be absolute, or at least close to absolute (a consonant is not a vowel), though in spelling such phonetically we would usually also invoke a vowel in the spelling, which allows for a rough rule of thumb. However, there is no absolute condition of being 'more consonant'. Nevertheless, the following example seems a fairly clear rendering (as does the XKCD example) of fortition, though in a different sense. Here:


In the process of removing the letters 'gh' to the word 'fight' the letter 't' is strengthened from a softer 'tuh' sound, to a stronger 'it' sound.

Another example would be with alphabetisms of already existing words, such as:

It (word)/IT (alphabetism)

Here in the word 'it,' the letter it is pronounce 'tuh' with a more vowel-like sound, as opposed to the alphabetism 'IT' where the 'T' is pronounced 'tee' with a stronger, more consonant-like sound.

Note here that despite the presence of the double 'ee' in the phonetic rendering of this pronunciation, this part of the word is destressed, and may therefore still be considered more 'consonant-like'.

  • I'll leave this up for a day or two and if no-one has any objections I'll accept this one as the more correct answer, as Mitch said. – user182372 Jun 25 '16 at 11:30
  • This also suffers from being about phonological phenomena that are not called fortition/lenition. herb(br)/herb(am) is a spelling pronunciation by the Brits (both were borrowed from the French who don't pronounce the 'aitch'. Fight/fit have identical 'unreleased' t's, it/IT are not cognately related. – Mitch Jun 25 '16 at 20:04
  • @Mitch What would be a more appropriate example? – user182372 Jun 25 '16 at 20:10
  • Actually the herb/erb pair is one of lenition, just be a more tangle path. IN an extremely oversimplified, at some point in the past the 'h' was pronounced, and then later on it was weakened so much that it was lost all together, in the process of lenition. – Mitch Jun 26 '16 at 0:20
  • I'm nudging you so I can clean up the comments on this question. – Kit Z. Fox Jul 14 '16 at 17:37

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy