"Referencive Nouns" as they're called in sudreil (Maybe there's some fancy linguistic term for them I'm oblivious to) do what they sound like; they reference something else. English has these as well, such as him, her, it, there, here, and others. These words have no specific meaning by themselves, but gain meaning by referencing something that was talked about in the past. For example, if I said "she is pretty", you would know that I find someone pretty but would have no idea who "she" is. If I pointed and said "she is pretty" however, you would now understand because the word she now has more meaning, due to the fact that you understand what the word she is referencing to.
2 Locational System in English (2LS):
In English's 2LS, there are only 2 words to reference location used in common everyday English (ex. "yonder" exists, but really is negligible due to its rarity."). Also, in English the only individuals perspective that matters is the speaker. Everything is relative to the speaker, and any relation of location to say the listener is not communicated.
3 Locational System in sudreil (3LS):
In sudreil's 3LS, referencive nouns take into consideration both the perspective of the listener and of the speaker. So in English, you could say "over there", but in sudreil you would say "over" ʃetwa or "over" eʒə, depending on whether the location was close to the listener.
2 Object Perspectives in English (3OPE)
2OPE is simple, however often leads to some confusion when using the word "that". While 3OPS does not entirely get rid of vagueness in conversation, specifying if the listener is close to what is being discussed leads to much greater clarity. An example would be "I want that phone". You might mean literately you want the phone that the listener currently owns, or simply one of the same make and model. In sudreil however, the distinction between du and vja would tell the listener if the speaker wants the listeners phone (du) or one that is not close to the speaker (vja).
3 Object Perspectives in sudreil (3OPS)
3OPS makes talking about objects more specific, and again takes the listeners perspective into account. So say you're at dinner, and you and a friend are sitting on one side of the table. You could say "pass me that drink", but lets say there are two drinks. In English, you would have to say the name of the drink or point; in sudreil, you could use du, ceiə, or vja to specify which drink you would like on the table.
Single Situational Perspective in English (1SPE)
3 Situational Perspectives in sudreil (3SPS)