Remark, observe indican poco más que el deseo de notar una cosa y de llamar la atención hacia ella <she remarked on her friend's excellent taste><after a pause, he observed that it was getting dark>.
Comment recalca a menudo una interpretación crítica <refused to comment about the situation>.
Note connota hacer mención especial de algo <in her report she noted the absence of birds on the island>.
Mention connota referirse a alguien o a algo brevemente <at the very end of the letter he mentioned the money she still owed him>.
