preterite vs used-to-be

preterite

adj

  • Belonging wholly to the past; passed by. 

  • showing an action at a determined moment in the past. 

noun

  • A grammatical tense or verb form serving to denote events that took place or were completed in the past. 

used-to-be

adj

  • Former, ex-. 

How often have the words preterite and used-to-be occurred in a corpus of books? (source: Google Ngram Viewer )