Colossians 4:6 Let your speech be always with grace, seasoned with salt, that ye may know how ye ought to answer every man.
Definition of diction: choice of words, especially with regard to correctness, clearness, or effectiveness.
That definition leaves out many things that occur in conversations. What if you said “Right!” but your tenor was one of sarcasm? That changes the meaning doesn’t it? Speech can be regional. What a word means in Maine isn’t always understood properly in Texas. Louisiana residence might understand Creole even if they are not Cajun. The rest of us often wonder if we heard right.
A tosser conversation is one in which words are thrown without regard of listener. It does not matter if anyone is listening, you are just filling the awkward silence with the sound of your own voice. Grace speech on the other hand is to be used to communicate important information. Effectiveness is vital if you are trying to communicate love and concern. Comfort is not comfort if sincerity is not transmitted. That takes more than mere words.
Knowing how to respond to people does not come from a familiarity with a dictionary. It comes from a heart of compassion, empathy and relationship. The same words mean more coming from people who have proven relationships. Relationship is the foundation of effectiveness; otherwise it is just a drive by shout out.
Grace speech requires that grace is in you, that it has been spread abroad in your heart first. The way to give grace in receiving grace first.
John 1:16-17 And of his fulness have all we received, and grace for grace. For the law was given by Moses, but grace and truth came by Jesus Christ