In phonetics, minimal pairs are pairs of words or phrases in a particular language, which differ in only one phoneme and have a distinct meaning. They are used to demonstrate that two phones constitute two separate phonemes in the language.
English "let" + "lit" proves that phones /e/ and /i/ do in fact represent distinct phonemes [e] and [i]. The phones do not have to be vowels, as the English minimal pair of "pat" + "bat" shows. In fact, this pair only differs in vocalization of the initial consonant as the configuration of the mouth is same for /p/ and /b/.
Following pairs prove existence of various distinct phonemes in English.
dime + time /d/ and /t/
rot + lot /r/ and /l/
zeal + seal /z/ and /s/
rhyme + time /r/ and /t/
meal + meet /l/ and /t/
feet + seat /f/ and /s/
On the other hand, phones /p/ in "spin" and /ph/ in "pin" are both allophones of the phoneme [p] and no minimal pair can be found to distinguish them. Languages like Cantonese distinguish between them and they represent distinct phonemes [p] and [ph].
Here is a minimal set in French:
cire wax sûre sure soeur sister sieur sir sueur sweatTo an Anglophone, some or all of these sound alike, because the [ö] and [ü] sounds do not exist in English. A minimal triplet of consonants is
bête noire [betnwar] black beast, pet peeve baie noire [benwar] black berry (not blackberry, which is mûre) baignoire [beñwar] bathtub[tn] is not a single phoneme in French, so this shows a minimal pair between the presence and absence of [t] next to [n], which shares its point of articulation. [n] and [ñ] 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:
qara' read, call qara` tear apart kara` kneelIn the following two hebrew verbs, the only distinction is a velar stop, in the middle of the first word:
lir'ot - to see lirot - to shootIn Korean, phones /r/ in Korea and /l/ in Seoul are allophones of the phoneme [l] and are perceived by native speakers of Korean as a single letter i.e. phoneme. The difference is that /r/ is pronounced before vowels.
In Spanish, /z/ and /s/ are both allophones of [s] and /z/ appears only before voiced consonants as in mismo /mizmo/. On the other hand, Spanish and Italian have many minimal pairs differing only in stress.