This article proposes that two linguistic systems (that is, two languages or registers) with different degrees of morphosyntactic integration of ideophones may apply the same restrictions on ideophones in different ways. In Study 1, the author shows quantitatively that the sentence-type restrictions reported for ideophones in several languages also constrain Japanese ideophones, but to a lesser extent. In Study 2, the author argues that two previously identified restrictions on Japanese ideophonic verbs appear to apply only partially to ideophonic verbs in baby talk and highly playful discourse. It is concluded that the strength of these restrictions is negatively correlated with the overall degree of morphosyntactic integration of ideophones in the language or register.
