Learning is a social process, where a learner's cognitive processes occur within social events that transpire when an individual interacts with people, objects and events in his or her culture and environment. This qualitative study of a small scale is grounded in the Socio Cultural Theory which postulates learning to be a social enterprise and supported by cultural tools which aid learning. The study was undertaken on a group of Malay tertiary learners to probe how far social sources, namely peers, impact their learning of vocabulary items in their preparation for the Malaysian University English Test (MUET). Besides social sources, the use of cultural tools, (namely, the dictionary and guessing meaning from context) were also probed to enquire how learners capitalise on these resources to make their learning process meaningful and to encourage autonomous learning. Data for the case study were collected through qualitative means of retrospective interviews and journal entries of the participants. The study found that cultural tools such as the dictionary and guessing meaning from context are useful sources for learning. Peers, as social sources, also play a significant role in improving the learners' affective states, since tasks carried out in groups are valued and held in importance, in accordance with the Malay cultural trait which emphasises group work and communal activities.