if the liquid metathesis is complete only if it occurred with the corresponding vowel lengthening, the metathesis occurred completely in south slavic and partially in slovak and in non-word-initial position in the whole czecho-slovak area. the complete metathesis has been operational in all slavic languages for acuted syllables. for word-initial non-acuted syllables, there was no lengthening except in south slavic and, partially, slovak.