This study employed both qualitative and quantitative methods (mixed method approach) to examine the influence of mother tongue on students’ performance in writing. A test in the form of a composition was administered to 50 randomly selected participants from Bangladesh, China, Indonesia, Singapore and Somalia. From each country, a native language expert was also interviewed. The findings from this study revealed that the errors made by the participants had a pattern that is linked to their mother tongues. This book will be of interest to researchers, instructors and students who are interested in error analysis and contrastive analysis. It will also give an insight to interested parties on how to carry out this kind of research by extending this methodology to different participants from different countries.