Family language policies encompass three components: language beliefs, language practices, and language management. This study focuses on language beliefs, which we approach from an attitudes perspective, presenting a corpus-assisted discourse study of parental attitudes towards childhood multilingualism. Based on corpora (over 30,000 words) comprising 742 Quebec-based parents’ responses to an open-ended survey question, we analyse frequencies, collocations, concordance lines, and longer text segments. Our findings confirm the multidimensionality of parental attitudes, providing new insights into the nature of the three previously-established dimensions – that is, status, solidarity, and cognitive development – as well as revealing a potential fourth dimension: namely personality development. Moreover, the findings show systematic differences between parents transmitting multiple societal languages versus parents transmitting heritage languages alongside one/more societal languages. The study makes an important contribution to the family language policy framework and language attitude theory more generally, and it facilitates the development of support measures for different types of multilingual families.