A mistake can be self-corrected, but an error cannot. Errors are likely to occur repeatedly and not recognized by the learner. As the errors commited by students are systematic and can function as learning tools, Corder combined error analysis with a growing interest in second language acquisition. The paper focuses on errors commited by non-native users of English due to various reasons. Errors are broadly categorized into functional and grammatical types. Further errors made in spoken, written and cultural aspects of the language are classified into “Phonological & Morphological levels”, “Syntactic, Grammatical & Semantic levels” and Cultural level” respectively. Errors can be looked upon as developmental phenomena providing evidence regarding the rules and categories used by the learners at a particular time. Thus the paper attempts to present the issues causing errors and draws attention to pin point some techniques to convert errors as learning tools. More