4 th ▁century ▁and ▁the ▁sound ▁ ▁began ▁to ▁develop ▁in ▁the ▁ 1 6 th ▁century ▁( see ▁below ). ▁Moreover , ▁it ▁is ▁clear ▁that ▁a ▁true ▁l isp ▁would ▁not ▁give ▁rise ▁to ▁the ▁system atic ▁distinction ▁between ▁ ▁and ▁ ▁that ▁character izes ▁Standard ▁Pen ins ular ▁pron unci ation . ▁For ▁example , ▁a ▁l isp ▁would ▁lead ▁one ▁to ▁pron ounce ▁both ▁ ▁(' I ▁feel ') ▁and ▁ ▁(' h undred ') ▁the ▁same ▁( as ▁) ▁whereas ▁in ▁standard ▁pen ins ular ▁Spanish ▁they ▁are ▁pron ounced ▁ ▁and ▁, ▁respectively . ▁ ▁For ▁native ▁speak ers ▁of ▁s ese o ▁vari eties ▁of ▁Spanish , ▁in ▁which ▁ ▁is ▁absent , ▁the ▁presence ▁of ▁this ▁ph on eme ▁in ▁European ▁speak ers ▁does ▁not ▁appear ▁strange . ▁However , ▁it ▁might ▁be ▁striking ▁for ▁learn ers ▁of ▁Spanish ▁in ▁North ▁America , ▁where ▁people ▁are ▁more ▁familiar ▁with ▁s ese o ▁pron unci ation , ▁and ▁indeed ▁gives ▁an ▁impression ▁of ▁" l isp iness ". ▁The ▁mis nom er ▁" Cast ilian ▁l isp " ▁is ▁used ▁occasionally ▁to ▁refer ▁to ▁this ▁aspect ▁of ▁Pen ins ular ▁pron unci ation ▁( in ▁both ▁dist in ción ▁and ▁ce ce o ▁vari eties ). ▁ ▁Historical ▁evolution ▁In ▁the ▁ 1 5 th ▁century , ▁Spanish ▁had ▁developed ▁a ▁large ▁number ▁of ▁s ibil ant ▁ph on emes : ▁seven ▁by ▁some ▁accounts , ▁eight ▁by ▁others ▁( dep ending ▁on ▁whether ▁ ▁and