Words: clitic
Part of speech: n
Definition: a word that is treated in pronunciation as forming a part of a neighboring word and that is often unaccented or contracted.
Example: Most languages can adopt theme-rheme structure idiosyncratically — as for English, we often use as for theme constructions — but topic-prominent languages use systematic changes in syntax or even dedicated morpological elements such as the Japanese clitic particle -wa to mark themes and to set them apart from rhemes.