C (hard) = K generally, as:—Declare = deklari, economy = ekonomio, decameter = dekametro, hectogram = hektogramo. In a few cases C becomes Ĉ, as:—Dedicate = dediĉi, carpenter = ĉarpentisto (probably from the French charpentier).
C (soft) generally undergoes no change, so remains C with its sound of TS, as:—Cipher = cifero, cigar = cigaro, glycerine = glicerino, grimace = grimaco, spice = spico. Some few words change to Z, as:—Price = prezo.
Ch (soft) = Ĉ generally, as:—Chamber = ĉambro, charming = ĉarma, chaste = ĉasta, chief = ĉefo.
Ch (hard) = Ĥ generally, as:—Chameleon = ĥameleono, chaos = ĥaoso, chemistry = ĥemio, cholera = ĥolero, hypochondria = hipoĥondrio, chorister = ĥoristo. It will be seen that these words are mostly derived from the Greek.
G (soft or hard) = G generally, as:—Geology = geologio, elegant = eleganta, general (officer) = generalo. The exceptions in which Ĝ is used are mostly words following the French pronunciation, as:—Danger = danĝero, garden = ĝardeno, general (adjective) = ĝenerala, germ = ĝermo, giraffe = ĝirafo, etc.
PH = F, as:—Elephantiasis = elefantiazo, sphere = sfero, etc.
QU = KV, as:—Equivalent = ekvivalenta, eloquent = elokventa, inquisition = inkvizicio, quantity = kvanto, quadratic = kvadrata.
S = S, but in a few instances it becomes Ŝ (probably following German pronunciation) as:—Slime = ŝlimo, smear = ŝmiri, spare = ŝpari, spin = ŝpini, etc.
S (sounded like Z) = Z generally, as:—Desert = dezerto, rose = rozo, present = prezenti, preside = prezidi, etc.
Sh = Ŝ generally, as:—Shark = ŝarko, ship = ŝipo, shoe = ŝuo.