PHRASEOLOGICAL SYNONYMS

I want to make my Phraseological Dictionary as helpful to the user as possible. I am making it also a dictionary of synonyms. For the entry Once in a blue moon, I give de uvas a peras, de pascuas a ramos, de higos a brevas and cada muerte de obispo. For each of the Spanish idioms I add, after once in a blue moon, every now and then. This is more painstaking but probably more helpful to the user, to the student who wishes to enhance their knowledge of phraseology in the other language.