faltering vs sure thing

faltering

adj

  • hesitant, halting 

noun

  • hesitancy 

sure thing

intj

  • An affirmative reply; yes; certainly. 

  • A polite reply to thank you. 

noun

  • That which is certain. 

How often have the words faltering and sure thing occurred in a corpus of books? (source: Google Ngram Viewer )