This paper reviews errors on grammatical, lexical, and phonological aspects of written and spoken English with theoretical background and procedure of error analysis. It empirically through qualitative and quantitative method finds out the errors in pronunciation, grammar, articles, auxiliaries, and prepositions and also reflects the possible reasons behind the errors in written and spoken English. Finally, it provides some recommendations for effective remedial measures and feedback techniques for developing spoken English in the light of the theoretical and empirical findings of the research.