Utterance particles are a characteristic feature of Cantonese and are essential for quick expression of speakers’ attitudes, assumptions, and feelings. The topic explored here is how the particles occur in combinations. Using the Natural Semantic Metalanguage (NSM) approach and data from the Hong Kong Cantonese Corpus, this paper highlights, firstly, that stable semantic explications for monosyllabic particles can be found. This runs counter to common assumptions that Cantonese particles are so contextually and/or pragmatically variable that it is impossible to pinpoint semantic invariants. It is furthermore shown that the meaning of polysyllabic particle “clusters”, i.e. cases where particles occur in immediate succession, is indeed the combined meaning of the component particles. This means that the particles zaa3 and wo3 combine semantically in the cluster zaa3-wo3. The explications are presented in both English-based and Cantonese-based NSM. Also considered are proposals that monosyllabic particles can be analysed as “contractions”, or even as combinations of “sub-syllabic morphemes” that do not occur on the surface, e.g. that zaa3 is a combination of the elements z- initial + aa rhyme + mid-level tone 3. Such analyses are rejected on semantic grounds. An alternative approach is suggested using the concept of phonaesthemes.