Linguists sometimes use the term "indexical" for a type of word or sign. If I understand the point, a word is "indexical" if it presupposes some aspect of the situation in which it is employed. "Here" is indexical. So, for that matter, is "there." Each presupposes that the speaker is located at a particular place, and that the listener has some idea what that place is. You ask a friend over the phone, "Do you know where my folder is?" Your friend replies, "Yes, you left it over here." In that case, the speech situation includes the fact that both he and I know that I was at his place the previous night, and I presume (he knows that I will presume) that he is speaking to me now from that home. So, because I understand the indexical use of the term, I know where my folder is. Likewise "now" is indexical. If I record the phrase "I am having trouble breathing now" and someone plays back that recording th...