What does it mean to have negative tone and negative diction vs. having positive tone and positive diction?
"Tone" suggests an attitude in the person expressing it. "Diction" refers the actual words used (lexical meaning). See the examples below.
'You should not be lounging on the grass" - negative tone
'A lawn is not for relaxation' - negative diction.
'You may find that the benches under the trees provide a comfortable place for relaxation' - positive tone
'Benches are provided for students during breaks.' - positive way of expressing theidea.