Between the first and the second palatalizations, new clusters "*tsy" and "*dzy" were formed by restoring a lost "*y" after the newly formed "*ts" and "*dz". That occurred only in morphologically transparent formations by analogy with similar formations in which "*y" was preceded by other consonants. In formations that were morphologically opaque and not understood as such by speakers of the time, the restoration did not take place and so "*ts" and "*dz" remained. Hence, depending on the type of formation, the pre-Proto-Greek sequences "*ty", "*tʰy" and "*dy" have different outcomes in the later languages. In particular, medial "*ty" becomes Attic "s" in opaque formations but "tt" in transparent formations.