/i/ at any level (/kaˈmitʃa/ → [kaˈmiːtʃa] ~ [kaˈmiːʃa]), but that underlying the same spelling <cia> in farmacia 'pharmacy' is a bisyllabic sequence consisting of the stressed syllable /tʃi/ and syllabic /a/ (/farmaˈtʃi.a/ → [farmaˈtʃiːa] ~ [farmaˈʃiːa]). Lenition Stop consonants shifted by lenition in Vulgar Latin in some areas. The voiced labial consonants and (represented by and , respectively) both developed a fricative as an intervocalic allophone. This is clear from the orthography; in medieval times, the spelling of a consonantal is often used for what had been a in Classical Latin, or the two spellings were used interchangeably. In many Romance languages (Italian, French, Portuguese, Romanian, etc.), this fricative later developed into a ; but in others (Spanish, Galician, some Catalan and Occitan dialects, etc.) reflexes of and simply merged into a single phoneme. Several other consonants were "softened" in intervocalic position in Western Romance (Spanish, Portuguese, French, Northern Italian), but normally not phonemically in the rest of Italy (except some cases of "elegant" or Ecclesiastical words), nor apparently at all in Romanian. The dividing line between the two sets of dialects is called the La Spezia–Rimini Line and is one of the most important isoglosses of the Romance dialects. The changes (instances of diachronic lenition resulting in phonological restructuring) are as follows: Single voiceless plosives became voiced: -p-, -t-, -c- > -b-, -d-, -g-. Subsequently, in some languages they were further weakened, either becoming fricatives or approximants, (as in Spanish) or disappearing entirely (as and , but not , in French). The following example shows progressive weakening of original /t/: e.g. vītam > Italian vita , Portuguese vida (European Portuguese ), Spanish vida (Southern Peninsular Spanish ), and French vie . Some scholars have speculated that these sound changes may be due in part to the influence of Continental Celtic languages, while scholarship of the past few decades has proposed internal motivations. The voiced plosives and tended to disappear. The plain sibilant -s- was also voiced to between vowels, although in many languages its spelling has not changed. (In Spanish, intervocalic was later devoiced back to ; is only found as an allophone of before voiced consonants in Modern Spanish.) The double plosives became single: -pp-, -tt-, -cc-, -bb-, -dd-, -gg- > -p-, -t-, -c-, -b-, -d-, -g- in most languages. Subsequently, in some languages the voiced forms were further weakened, either becoming fricatives or approximants, (as in