foot (pl. feet)
How we get from the Proto-Indo-European word to the English and the Spanish ones is easy to explain by regular sound-change rules that have been well known for over a century. So, as we said, in the Germanic branch of daughter languages, Proto-Indo-European p changed to f and d changed to t, both changes predicted by Grimm’s Law (see, Part I, §3.6.5).
The relationship between the singular and the plural of the English word (foot-feet) is also explained by a regular phenomenon known as i-mutation, umlaut, or metaphony, by which a back vowel, in this case the /ʊ/ in the singular word foot, becomes fronted to /i/ in anticipation of a similar sound in the suffix (cf. Part I, Chapter 7). This is a sound mutation that took place in many Germanic languages around 1,500 years ago.
Latin pĕdem > pede > piede > piee > Mod. Spanish pie
- Mod. French pied (Old French pié): the d, which is not pronounced, was added in recent times to the spelling of the word to make it look more like its Latin source word
- Portuguese pé (Old Port. pee): in Portugues, Latin short ĕ did not become a diphthong
- Catalan peu (a variant of Old Provençal pe)
- Italian piede: here the ĕ became a diphthong, but the d was not lost
English foot and Spanish pie are not the only patrimonial cognates that refer to body parts, though there aren’t very many of them. We find a few other such cognates, having to do with body parts. Sometimes, such pairs are not full cognates (sharing the root and all affixes), but they at least share the word’s root in the original source word. All of those pairs of cognates look very different from each other at first sight in the modern languages, since they split from the original source word thousands of years ago and the sounds in these words have mutated independently of each other (though not their meaning, in this case). The main such cognate words are the following:
- Eng. tongue ~ Sp. lengua are also cognates (it was dingua in Old Latin; cf. Chapter 16).
- Eng. tear ~ Sp. lágrima (from Latin lācrima, which comes from an earlier dacruma),
- Eng. tooth ~ Sp. diente (from Latin dent‑)
- Eng. ear ~ Sp. oreja (which comes from a diminutive of the Latin root aur‑)
- Eng. eye (from Old English ēaġe) ~ Sp. ojo (from Latin ocul‑)
- Eng. heart ~ Sp. corazón (from a word derived from Latin cord‑)
- Eng. nose ~ nariz (derived from Latin nār‑is, from nās-us, with rhotacism of the s)