Fifty composition papers were used as the basis for error analysis. Fifty students of both sexes at their first and second year of study at Mosul Technical Institute in Mosul were asked to write a short essay on described and explained. It has been found that these writers commit all errors that one can think of. The errors were classified under the following headings: spelling, sentences structure, verb groups, adjectives, prepositions, and vocabulary. Interferenc from Arabic constructs a major source of errors. Many other sources for errors are also pointed out which are related to the teaching materials and the learning process of the target language.