∕∕  
  “We distinguish between … & … ” that means: We some times sometimes use the expression “I lied when I said that I saw green”
as opposed to
sometimes
“I told the truth when I said ‘ … ’”. But isn't this enough? – “But under what circumstances do you use the expression ‘ … ’”? But must I necessarily stopp giving you circumstances with when I have given you a sample? Why not when I have given you a word, a verbal expression? Is the use of such an expression necessarily indefinite as compared
with the use of a sample – ( can't a sample be used, compared with objects, in many different ways?