Among the Igbo people of South Eastern Nigeria, the art of conversation is regarded very highly and proverbs are seen as "abubo e ji eri okwu" that is (condiments to speech) or literally defined as "the palm oil and salt with which words are eaten". Igbo proverbs have aesthetic appeals which have revealed that apart from being the store house of the people‟s wisdom, they appeal to their various senses. The study sets out to examine the common themes and aesthetic devices of Igbo proverbs in order to ascertain the extent to which they affect understanding, meaning and function in communication. As proverbs add sense to discourse, the study portrays that an understanding and effective interpretation of Igbo proverbs depend largely on the knowledge of the different themes in which they are couched and the utilization of the aesthetic devices embedded in them. The study is built on Traditional grammar and Functional grammar. Using Traditional grammar, the study examines the common themes of the proverbs. The theoretical framework for the study is based on the systemic functional linguistic (SFL). Approach to language study proposed by Halliday and Hassan (1985), Butt, Fahey, Spinks, Yallop (1999) and also Halliday and Maitthiessen (2004). The SFL theory is used to analyse the context of culture, context of situation and metafunctional components of the text. These consist of the variables of field, tenor and mode of discourse. These three parameters of context of situation affect our language choices because they reflect the three main uses of language identified by Halliday and Maitthiessen (2004) as the three metafunctions of language - ideational, interpersonal and textual, but the analysis focuses on the first two. The study analysed 40 Igbo proverbs randomly selected from the 200 Igbo proverbs obtained through audio recording and observation of live performances during formal and informal occasions involving Igbo people. Books on Igbo proverbs and interviews with four elderly Igbo men, two elderly women and four youths helped a great deal. The study found that Igbo proverbs are a repository of several aspects of the culture, orature and linguistic habits of the Igbo people. Another finding of the study is that the appreciation of the full functionality of a proverb is a property of the context of use, and the theme of the proverb influences this. The study concludes that the knowledge of the different contextual features facilitate the negotiation of the meaning of Igbo proverbs.