The thing is [t] and [d] started palatalizing and later to merge with the preceding [j] producing the affricates [tʃ] and [dʒ] already in the eighteenth century. First [t] became [ʃ] in words like nation, then, later, the palatization extended to other environments (words like nature, mutual etc.)

Nowadays jod-coalization is becoming the norm also in stressed syllables tuesday sounding like "choose day", homophony between dune and june etc.

The thing is [t] and [d] started palatalizing and later to merge with the following [j] producing the affricates [tʃ] and [dʒ] already in the eighteenth century. First [t] became [ʃ] in words like nation, then, later, the palatization extended to other environments (words like nature, mutual etc.)

Nowadays jod-coalization is becoming the norm also in stressed syllables tuesday sounding like "choose day", homophony between dune and june etc.