The present paper brings evidence to the pervasiveness of metonymy at different levels of grammar, ranging from categorial and subcategorial conversions to modality. Ruiz de Mendoza (2000) has divided metonymies into two groups, namely source-in-target and target-in-source metonymies. In the case of the former the source domain is incorporated in the target domain whereas in the case of the latter the target can never be a central subdomain of the source. For example, the use of the deverbal noun ‘cut’ in He made a deep cut in his knee is grounded in the target-in-source metonymy ACTION FOR RESULT which changes the syntactic organization of the clause (He cut his knee deeply). The metonymy OBLIGATION FOR DESIRE explains why the modal auxiliary ‘must’, which usually expresses obligation, can be used to convey the speaker’s desire to carry out an action (e.g. I must speak to you, please).