▁while ▁ ▁represented ▁the ▁vo iced ▁pal atal ▁ ▁( as ▁in ▁ ▁' son '). ▁ ▁With ▁the ▁changes ▁of ▁s ibil ants ▁in ▁the ▁ 1 6 th ▁century , ▁the ▁two ▁sounds ▁merged ▁as ▁ ▁( l ater ▁to ▁become ▁vel ar ▁), ▁and ▁the ▁letter ▁ ▁was ▁chosen ▁for ▁the ▁single ▁resulting ▁ph on eme ▁in ▁ 1 8 1 5 . ▁ ▁This ▁results ▁in ▁some ▁words ▁that ▁originally ▁contained ▁ ▁now ▁containing ▁, ▁most ▁easily ▁seen ▁in ▁the ▁case ▁of ▁those ▁with ▁English ▁cogn ates , ▁such ▁as ▁ej erc icio , ▁" ex erc ise ". ▁When ▁C erv antes ▁wrote ▁Don ▁Qu ix ote ▁he ▁sp elled ▁the ▁name ▁in ▁the ▁old ▁way ▁( and ▁English ▁pres erves ▁the ▁), ▁but ▁modern ▁ed itions ▁in ▁Spanish ▁spell ▁it ▁with ▁. ▁For ▁the ▁use ▁of ▁ ▁in ▁Mexico — and ▁in ▁the ▁name ▁México ▁itself — see ▁below . ▁ ▁The ▁letter ▁ ▁( c - ced illa ) — which ▁was ▁first ▁used ▁in ▁Old ▁Spanish — is ▁now ▁ob sole te ▁in ▁Spanish , ▁having ▁merged ▁with ▁ ▁in ▁a ▁process ▁similar ▁to ▁that ▁of ▁ ▁and ▁. ▁Old ▁Spanish ▁, ▁, ▁ ▁became ▁modern ▁, ▁, ▁. ▁ ▁W ords ▁formerly ▁sp elled ▁with ▁ ▁or ▁ ▁( such ▁as ▁, ▁, ▁and ▁) ▁are ▁now ▁written ▁with ▁ ▁and ▁ ▁( , ▁, ▁, ▁respectively ). ▁ ▁The ▁sequences ▁ ▁and ▁ ▁do ▁not ▁occur ▁in ▁modern ▁Spanish ▁except ▁some ▁loan words