The purpose of this study is to present a contrastive analysis of the different types of interrogative sentences in English and Vietnamese including their structures and meanings. It is also hoped that the result of this study will be of some use to English teachers in Vietnam in their classroom teaching and in their preparation of teaching materials. It may also be useful to Vietnamese students who are learning English, especially when learning the English interrogative mood. Hitherto, there have been different models of description of language, but the systemic model is considered to be one of the most comprehensive, since it is able to bring out the functional uses of language and can be used to describe any language. For this reason, the systemic model is adopted in this paper to describe the two systems of the English and Vietnamese interrogative mood. The varieties of the two languages, English and Vietnamese, from which examples are taken for analysis in this paper, are Southern British Standard and Standard Vietnamese ranging from colloquial to literary. Throughout each chapter, the examples are numbered in consecutive order. Examples in Vietnamese are presented with a slash mark ( / ) placed between lexical items to facilitate the matching of Vietnamese with the literal English translation which follows. The literal translation is followed by a freer English translation enclosed in quotation marks. The study consists of five chapters. In the first chapter, the author begins by summarizing different views on the nature of language and their applications in language teaching and learning, and then presents a short introduction to systemic linguistics and a brief sketch of systemic grammar. The second chapter is about the English interrogative mood. This description of the English interrogative mood is largely based on the ideas on Mood presented by D. J. Young, lecturer in English in the University of Wales Institute of Science and Technology in Britain. In the third chapter, an attempt is made to provide a detailed description of the different types of interrogative sentences in Vietnamese. Chapter four moves to a contrastive analysis which consists of a textual and then a systemic comparison and contrast of the two interrogative mood systems in English and Vietnamese. A recapitulation of what has been done in the previous chapters and some suggestions for the preparation of teaching material and the teaching of English interrogative sentences to Vietnamese students are presented in chapter five, which is the last chapter of the study.