We compared dyad-focused maternal speech (protoconversations and maternal speech describing the dyad) in interactions of mothers with their twin and singleton infants. Nine twins and nine singletons, coming from urban areas of Crete (Greece), were video-recorded at home in spontaneous face-to-face interactions with their mothers, from the 2nd to the 6th month at 30-day intervals. Continuous micro-analysis revealed that the following: (a) variations in proto-conversations favoured singleton compared to twin infants; (b) twin and singleton mothers addressed different, but possibly of equivalent communicative significance, verbal comments to their infants within protoconversations; (c) both twin and singleton mothers showed age-variant efforts for conversation with their young infants. Though we showed quantitative variations of maternal dyad-focused speech between mother-singleton infant and mother-twin infant dyads, both singleton and twin mothers used devices of equivalent communicative significance and age-variant attempts to respond sensitively to their infants' expressive behaviours according to the latter's age-related motives for communication.