declare vs speak

declare

verb
  • To assert or announce formally, officially, explicitly, or emphatically. 

  • To make outstanding debts, e.g. taxes, payable. 

  • To show one's cards in order to score. 

  • To explicitly establish the existence of (a variable, function, etc.) without necessarily describing its content. 

  • For a constituency in an election to officially announce the result 

  • For the captain of the batting side to announce the innings complete even though all batsmen have not been dismissed. 

  • To inform government customs or taxation officials of goods one is importing or of income, expenses, or other circumstances affecting one's taxes. 

speak

verb
  • To communicate (some fact or feeling); to bespeak, to indicate. 

  • To communicate with one's voice, to say words out loud. 

  • To understand (as though it were a language). 

  • To have a conversation. 

  • To utter. 

  • To produce a sound; to sound. 

  • To be able to communicate in a language. 

  • Of a bird, to be able to vocally reproduce words or phrases from a human language. 

  • To deliver a message to a group; to deliver a speech. 

  • To be able to communicate in the manner of specialists in a field. 

  • To communicate or converse by some means other than orally, such as writing or facial expressions. 

noun
  • Speech, conversation. 

  • language, jargon, or terminology used uniquely in a particular environment or group. 

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