ahead vs than

ahead

adv
  • To a later time. 

  • At an earlier time; beforehand; in advance. 

  • To an earlier time. 

  • In or for the future. 

  • At or towards the front; in the direction one is facing or moving. 

  • So as to be further advanced, either spatially or in an abstract sense. 

than

adv
  • At that time; then. 

prep
  • introduces a comparison, and is associated with comparatives, and with words such as more, less, and fewer. Typically, it seeks to measure the force of an adjective or similar description between two predicates. 

conj
  • Used in comparisons, to introduce the basis of comparison. 

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