in most languages, with the prominent exceptions of French and Spanish, where it represents before vowels (or various similar fricatives such as the palatal fricative , in Spanish), and the vowel or semivowel elsewhere. Z: In most languages it represents the sound . However, in Italian it denotes the affricates and (which are two separate phonemes, but rarely contrast; among the few examples of minimal pairs are "ray" with , "race" with (note that both are phonetically long between vowels); in Romansh the voiceless affricate ; and in Galician and Spanish it denotes either the voiceless dental fricative or . Otherwise, letters that are not combined as digraphs generally represent the same phonemes as suggested by the International Phonetic Alphabet (IPA), whose design was, in fact, greatly influenced by Romance spelling systems. Digraphs and trigraphs Since most Romance languages have more sounds than can be accommodated in the Roman Latin alphabet they all resort to the use of digraphs and trigraphs – combinations of two or three letters with a single phonemic value. The concept (but not the actual combinations) is derived from Classical Latin, which used, for example, TH, PH, and CH when transliterating the Greek letters "θ", "ϕ" (later "φ"), and "χ". These were once aspirated sounds in Greek before changing to corresponding fricatives, and the H represented what sounded to the Romans like an following , , and respectively. Some of the digraphs used in modern scripts are: CI: used in Italian, Romance languages in Italy, Corsican and Romanian to represent before A, O, or U. CH: used in Italian, Romance languages in Italy, Corsican, Romanian, Romansh and Sardinian to represent before E or I (including yod ); in Occitan, Spanish, Astur-leonese and Galician; or in Romansh before A, O or U; and in most other languages. In Catalan it is used in some old spelling conventions for . DD: used in Sicilian and Sardinian to represent the voiced retroflex plosive . In recent history more accurately transcribed as DDH. DJ: used in Walloon and Catalan for . GI: used in Italian, Romance languages in Italy, Corsican and Romanian to represent before A, O, or U, and in Romansh to represent or or (before A, E, O, and U) or GH: used in Italian, Romance languages in Italy, Corsican, Romanian, Romansh and Sardinian to represent before E or I (including yod ), and in Galician for the