▁Republic ▁motor cycle ▁Grand ▁Prix ▁Czech ▁Republic ▁Motor cycle ▁Grand ▁Prix <0x0A> </s> ▁I - mut ation ▁( also ▁known ▁as ▁um la ut , ▁front ▁mut ation , ▁i - um la ut , ▁i / j - mut ation ▁or ▁i / j - um la ut ) ▁is ▁a ▁type ▁of ▁sound ▁change ▁in ▁which ▁a ▁back ▁v owel ▁is ▁front ed ▁or ▁a ▁front ▁v owel ▁is ▁raised ▁if ▁the ▁following ▁sy ll able ▁contains ▁, ▁ ▁or ▁ ▁( a ▁vo iced ▁pal atal ▁approxim ant , ▁sometimes ▁called ▁y od , ▁the ▁sound ▁of ▁English ▁ ▁in ▁yes ). ▁It ▁is ▁a ▁category ▁of ▁re gress ive ▁met aph ony , ▁or ▁v owel ▁harm ony . ▁ ▁The ▁term ▁is ▁usually ▁used ▁by ▁sch ol ars ▁of ▁the ▁German ic ▁languages : ▁it ▁is ▁particularly ▁important ▁in ▁the ▁history ▁of ▁the ▁German ic ▁languages ▁because ▁inf lection al ▁suffix es ▁with ▁an ▁/ i / ▁or ▁/ j / ▁led ▁to ▁many ▁v owel ▁altern ations ▁that ▁are ▁still ▁important ▁in ▁the ▁morph ology ▁of ▁the ▁languages . ▁ ▁German ic ▁languages ▁ ▁I - mut ation ▁took ▁place ▁separately ▁in ▁the ▁various ▁German ic ▁languages ▁from ▁around ▁ 4 5 0 ▁or ▁ 5 0 0 ▁AD ▁in ▁the ▁North ▁Sea ▁area ▁and ▁affected ▁all ▁the ▁early ▁languages ▁except ▁for ▁Goth ic . ▁It ▁seems ▁to ▁have ▁taken ▁effect ▁earliest ▁and ▁most ▁completely ▁Old ▁English ▁and ▁Old ▁Nor se . ▁It ▁took ▁place ▁later ▁in