The delay in the development of the language often found in twins is usually interpreted as being strictly connected with the twinning situation and on the assumption that a model of verbal, tendentially crypto-phasic, communication would more easily exist between twins. Two types of language pathology in twins, diverging from this classic framework, are presented: (1) Developmental dyslalia (or developmental dysarthria); in these cases no abnormality could be found in the modality of verbal communication between the cotwin; (2) Developmental dysphasia; in these cases not only no tendency toward cryptophasia was observed, but indeed the verbal communication between the twins was markedly reduced. These two types of language disorders, as well as the classic one, are discussed in the light of a neurolinguistic interpretation.