no strings attached vs surely

no strings attached

adv

  • Without conditions or obligations; without a catch. 

adj

  • Characterized by an absence of conditions or obligations. 

surely

adv

  • Without fail. 

  • Certainly, undoubtedly. 

  • With confidence. 

How often have the words no strings attached and surely occurred in a corpus of books? (source: Google Ngram Viewer )