Grammatical particle

In grammar, the term particle (abbreviated PTCL) has a traditional meaning, as a part of speech that cannot be inflected, and a modern meaning, as a function word (functor) associated with another word or phrase, in order to impart meaning. Although a particle may have an intrinsic meaning, and may fit into other grammatical categories, the fundamental idea of the particle is to add context to the sentence, expressing a mood or indicating a specific action.

In English, for example, the phrase "oh well" has no purpose in speech other than to convey a mood. The word 'up' would be a particle in the phrase to 'look up' (as in the phrase "look up this topic"), implying that one researches something, rather than literally gazing skywards. Many languages use particles, in varying amounts and for varying reasons. In Hindi, they may be used as honorifics, or to indicate emphasis or negation. In some languages they are clearly defined, e.g. Chinese which has three types of zhùcí (助詞; particles): Structural, Aspectual, and Modal. Structural particles are used for grammatical relations. Aspectual particles signal grammatical aspects. Modal particles express linguistic modality. Polynesian languages, which are almost devoid of inflection, use particles extensively to indicate mood, tense, and case.