Minimal pair

In phonology, minimal pairs are pairs of words or phrases in a particular language, which differ in only one phonological element, such as a phone, phoneme, toneme or chroneme and have a distinct meaning. They are used to demonstrate that two phones constitute two separate phonemes in the language.

As an example for English vowels, the pair "let" + "lit" proves that the phones (in let) and  (in lit) do in fact represent distinct phonemes  and. An example for English consonants is the minimal pair of "pat" + "bat". In phonetics, this pair, like any other, differs in number of ways. In this case, the contrast appears largely to be conveyed with a difference in the voice onset time of the initial consonant as the configuration of the mouth is same for and ; however, there is also a possible difference in duration, which visual analysis using high quality video supports.

Phonemic differentiation may vary between different dialects of a language, so that a particular minimal pair in one accent is a pair of homophones in another. This does not necessarily mean that one of the phonemes is absent in the homonym accent; merely that it is not present in the same range of contexts.

Differentiations in English
Following pairs prove existence of various distinct phonemes in English.

Differentiating consonants with same location and manner of articulation
In the articulation of bilabial plosives, 4 phones are defined by the characteristics voiced/unvoiced and aspirated/unaspirated:, , and. In different languages only some of these may occur and the number of phonemes formed may be different again.

Differentiating vowels
The following table shows a minimal set in French distinguishing vowels, some or all of which may sound alike to an Anglophone, because the and  sounds do not exist in English:

Differentiating consonants
A minimal triplet of consonants in French is:

Because is not a single phoneme in French, this shows a minimal pair between the presence and absence of  next to, which shares its point of articulation. and differ only in point of articulation.

There are three verbs in Hebrew which demonstrate the distinction, in some dialects, between a velar stop and an uvular stop on one hand, and a glottal stop with and without tightening of the throat on the other:

In the following two Hebrew verbs, the only distinction is a glottal stop in the middle of the first word:

In Korean, phones in "Korea' and  in "Seoul" are allophones of one phoneme and are perceived by native speakers of Korean as a single phoneme. The difference is that  is an allophone of this phoneme before vowels.

In Spanish, and  are both allophones of. appears only before voiced consonants as in mismo.

Differentiating chronemes
Hungarian and Italian have distinctive length of consonants, as did Latin. A differentiator for length may be called a chroneme. In the International Phonetic Alphabet (IPA), lengthening can be indicated by doubling the symbol, or by the special sign. Doubling is commonly used for consonants, while the special symbol is used for vowels. E.g. in Italian:

Hungarian, German and Thai have distinctive vowel length, as did Latin. E.g. in Thai (and compare this example also to the one on tone):

Differentiating tonemes
Languages such as Mandarin Chinese, Thai and many African languages. (See: pitch accent and tonal language.) For example in Thai:

Differentiating stress
Spanish, Portuguese, Romanian and Italian have many minimal pairs differing only in stress. Dutch has several, e.g. (stress indicated by acute accent):

Minimal pairs may differ superficially in more than one place if one feature is dependent on the other. For example, English record (noun) and record (verb) (and similar pairs) appear superficially not to be minimal pairs for stress because they differ in vowel quality as well. However, since the differences in vowel quality are predictable consequences of the differences in stress, such pairs are considered minimal pairs. The case is similar in Russian, eg. мука ('torture, pain') and мука ('flour').