are known as zhùcí (simplified Chinese: 助词; traditional Chinese: 助詞) or yǔzhùcí (语助词; 語助詞).[1] They belong to function words (虚词; 虛詞; xūcí). In other words...

function words, including most grammatical particles, or postpositions (joshi (助詞))—small, usually common words that, for example, mark sentence topics, subjects...