2012, Michael Silverstein, “The[] walked down the street”, inLondon Review of Books, volume34, number21:
In order that they might represent the worlds of experience and imagination, such symbols have to be put together with ‘indexical’ signs, as Peirce termed them, such as articles (the, some), demonstratives (this, those), tense-inflections (walk-s, walk-ed), moods (may/might walk, shall/should walk) etc.