1‘her mother looked concerned’
worried, anxious, disturbed, perturbed, troubled, bothered, distressed, upset, disquieted, uneasy, ill at ease, apprehensive, agitated
2‘I'm gratified to find that you are so concerned about my welfare’
attentive to, considerate of
3‘all concerned parties’
interested, involved, affected
connected, related, implicated
We take a look at several popular, though confusing, punctuation marks.