This paper extends the concept of local grammar to speech act studies, focusing specifically on apologising in English. It aims primarily to demonstrate the usefulness of a local grammar approach to account for speech acts and ultimately to contribute to the on-going development of corpus pragmatics. Apology expressions in a corpus of scripted TV conversations are first automatically extracted and then manually examined in order to make sure that all remaining instances have the illocutionary force of apologising and thus qualify for further analysis. The subsequent local grammar analyses facilitate the establishment of a local grammar of apology, comprising 14 local grammar patterns. The analyses show that it is promising to develop a set of local grammars to account more adequately for speech acts in general. The relationship between local grammars, functional grammars, and general grammars is further discussed, which suggests that local grammars can be an alternative approach to functional-pragmatic studies of language and discourse. Directions for future research are outlined; and implications and applications are briefly discussed.