hubieran dulcificado
-they/you had sweetened
Antecopréterito de subjuntivo para el sujetoellos/ellas/ustedesdel verbodulcificar.

dulcificar

Si su carácter y su predicación se hubieran dulcificado por la experiencia evangélica que obtuvo posteriormente, su trabajo misionero en América habría sido probablemente más productivo.
Had his character and preaching been softened by that evangelical experience which he subsequently obtained, his missionary work in America would probably have been more productive.
Palabra del día
hervir a fuego lento