In linguistics, particles are small words that do not change form and often serve a grammatical function. They can indicate relationships between words, express modality, or add emphasis. Common examples include words like "not," "up," and "out." Particles can be found in various languages and often play a crucial role in sentence structure. Particles can also be part of phrasal verbs, where they combine with verbs to create new meanings. For instance, in the phrase "give up," the particle "up" alters the meaning of "give." Understanding particles is essential for grasping the nuances of language and communication.