Spanish (along with English and many other languages) has inferential sentences such as No es que no quiera: Es que no sabe querer, ‘It’s not that she doesn’t love; it’s that she doesn’t know how to love.’ We describe the grammar and pragmatics of these sentences and show how their pragmatic characteristics follow from their grammar and the principles of relevance theory. Inferentials consist of a finite clause embedded as the complement of an expletive copular matrix clause, which may be modified by a focusing particle and/or a negator. Inferentials function as metalinguistic devices which characterize the relevance of the proposition represented by their clause to the processing of an utterance. Negative inferentials characterize that proposition as likely to be considered in the processing but they deny its relevance; positive inferentials characterize the proposition as unlikely to be considered but they assert its relevance. The inferential proposition may be interpreted as an implicated premise or conclusion. If it is taken as an implicated premise then it may be further interpreted as an explanation, reason, or cause; if it is taken as an implicated conclusion then it may be further interpreted as a result, consequence, or conclusion. It may also be taken as a (re)interpretation or reformulation of the target utterance.