Hello. You did not say which Miller work this question refers to, which makes it impossible for it to be answered accurately.
However, the endings are terminal elements in words that have the objective of flexing them and keeping them in agreement with the number and gender of the words and the way and tense that the sentence presents. Thus, we can consider that the use of endings in a similar way, in Miller's work, was made not only to create verbal and nominal agreement, but to create a feeling of stability and sameness in the reader. Indicating that something would not change for a long time.
