Catalan is a Romance language spoken by some 11 million people, in Catalonia (Catalunya), Andorra, north Catalonia (Catalunya Nord), the Valencian Country (País Valencia), the Balearic Islands (Illes Balears), an adjacent strip of Aragonese lands (also known as la Franja) and Sardinian city of l'Alguer (Alghero) (all these also known as the Catalan Countries).
A summary of the phonemes of Catalan, their graphemes and sounds:
Notes on ASCII IPA usage: . Z - palatal voiced sibillant, as in French 'oGNon' . S - palatal voiceless sibillant, as in English 'fiSH' . <NY> - palatal nasal, as in French 'oGNon', Hungarian 'aNYu' . <LY> - palatal lateral, as in Italian 'aGLIo' . <rr> - multiple thrill vibrant, as in Spanish 'pueRRo' . @ - unstressed neutral vowel, as in English 'thE thing' . O - low rounded back vowel . E - ow unrounded front vowel, as in English 'pEt'
PLOSIVES Plosives in final position become voiceless. /p/ 'p' /b/ 'b','v' (see /v/ below)
[B] between vowels or liquides; [p] in final position
/t/ 't' /d/ 'd'
[D] between vowels or liquides; [t] in final position
/k/ 'c' before 'a,o,u'; 'qu' before 'e,i'
'qu' for /kw/ before 'a,o,u'; 'qü' for /kw/ before 'e,i'
/g/ 'g' before 'a,o,u'; 'gu' before 'e,i'
'gu' for /gw/ before 'a,o,u'; 'gü' for /gw/ before 'e,i' [G] between vowels or liquides, [k] in final position
AFFRICATES Affricates in final position become voiceless. Word final /ts,tS/ followed by a vowel become voiced (liaison). /ts/ 'ts'
(not considered a separate phoneme, but t+s, by Alarcos, Badia, Wheeler)
/dz/ 'tz'
(not considered a separate phoneme, but t+s, by Alarcos, Wheeler)
/tS/ 'tx'; sometimes 'ig' after vowels; many exceptions
(not considered a separate phoneme, but t+s, by Alarcos, Wheeler)
/dZ/ 'tj' before 'a,o,u'; 'tg' before 'e,i'; many exceptions
(not considered a separate phoneme, but t+s, by Alarcos, Wheeler)
FRICATIVES Fricatives in final position become voiceless. Word final /s,S/ followed by a vowel become voiced (liaison). /f/ 'f' /v/ 'v'
As a separate phoneme from 'b', only in Balearic, Valencian, and areas around Valls.
/s/ 's'; 'ss' between vowels; also 'c' before 'e,i' and 'ç' elsewhere /z/ 'z'; 's' between vowels /S/ 'x'; 'ix' after vowel
In Occidental variants (Lleida, Valencian), the written form -ix- is pronounced [jS]. In Barcelona, initial 'x' is pronounced as affricate [tS].
/Z/ 'j' before 'a,o,u'; 'g' before 'e,i'; many exceptions
In Barcelona, initial 'j' is pronounced as affricate [dZ].
NASALS Nasals in final position retain distinct point or articulation, unlike in Spanish or French. /m/ 'm' /n/ 'n' /<NY>/ 'ny'
LIQUIDS /l/ 'l', 'l·l' (this is 'ele geminada', a Catalan characteristic grapheme)
Catalan /l/ has a distictive velar resonance, unlike Spanish or French ones.
/<LY>/ 'll'
Catalan /<LY>/ has not merged with /j/, unlike Spanish or French ones did.
/r/ 'r' between vowels; and complementary distribution with /<rr>/ /<rr>/ word initial 'r'; 'rr' between vowels
(considered as a complmentary variant of /r/ by Wheeler)
VOWELS In the Standard vocalic system, only [@,i,u] can appear in unstressed positions. In Balearics, /@/ 'e', can be a distinct phoneme as well in stressed position. /A/ 'a'; 'à'.
Catalan /A/ is tenser and more open than the Spanish or French ones. Only in stressed position. When unstresssed coalesces to [@], but not in Occidental variants (Lleida, Valencian).
/E/ 'e'; 'è'.
Only in stressed position. When unstresssed coalesces to [@], but in Occidental variants (Lleida, Valencian) to [e].
/e/ 'e'; 'é'.
Only in stressed position. When unstresssed coalesces to [@], but not in Occidental variants (Lleida, Valencian).
/i/ 'i'; 'í'; 'ï'. /O/ 'o'; 'ò'.
Only in stressed position. When unstresssed coalesces to [u]. but in Occidental variants (Lleida, Valencian) and in some places of Balearics to [o].
/o/ 'o'; 'ó'.
Only in stressed position. When unstresssed coalesces to [u]. but not in Occidental variants (Lleida, Valencian) and in some places of Balearics.
/u/ 'u'; 'ú'; 'ü'.
There is a Catalan Wikipedia.
(Also, we need a good English-language article about Catalan langauge here.)