Teachers of English often point out the fact that university learners still make basic prepositional errors in their writing. Since there is a dearth of research work pertaining to the acquisition of English prepositions in Sri Lanka, my endeavour is to take a further step toward investigating and gaining a comprehensive understanding of this prepositional problem. This book is an attempt to investigate how the ESL learners at university level acquire English prepositions and identify the nature of difficulties encountered by Sri Lankan Second Language learners of English (ESL) with regard to the uses of prepositions in English Language.The Prepositions "at","in","by","with" were selected for this study. These prepositions were selected because they were the most commonly used ones by ESL learners and consequently more errors were detected with related to their uses as compared to the frequency of errors made in the use of other Prepositions.Moreover,this book draws readers' attention into several facets of pedagogical implications coupled with classroom activities for common errors of English prepositions in ESL classrooms.