early on vs immature

early on

adj

  • Early in a process. 

adv

  • At an early stage. 

immature

adj

  • Not fully formed or developed; not grown. 

  • Childish in behavior; juvenile. 

noun

  • An immature member of a species. 

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