I think it is a linguistic universal that all languages have deictic words. They all have first-person pronouns and words like ‘here’ and ‘now’. This makes sense since these are very useful and it would be hard to get along without them. It would be interesting to see what indexical/deictic words are universal. It would also be neat to figure out what other indexicals there could be but are not found in any actual languages. For example, we could easily create a me-complement which refers to everybody besides the speaker. Would any others be useful? Would any others be philosophically interesting? Maybe plural indexicals that specify numbers of people, like ‘2-we’ for a group of two people. One question that would be worth exploring is whether there are any indexicals which are not found in English but are in other languages and what the differences are. There is the usual example of tu/vous in French which carry different levels of familiarity with the addressee, but these are accommodated to ‘you’ in a straightforward way. Are there any more exotic ones?