In this study, 160 trainees and five English teachers were involved. Of the 160 trainees,rn80 from Asella TTI and the remaining 80 from Dessie TTI were native speakers ofrnOromo and Amharic, respectively. Similarly, three of the teachers from Asella and twornfrom Dessie were native speakers of the above languages, respectively. Except thernteachers, trainees from both TTI's were selected with the help of the Table of RandomrnNumbers.rnThe main purpose of the study was, however, to investigate English spelling errorsrnamong Oromo trainees at Asella TTI. Trainees from Dessie were included to identifyrnspelling errors that were particular to trainees at Asella TTI. The English teachers werernalso included to have more points of reference and see whether or not the teachersrncommit the same spelling errors.rnTo elicit the possible spelling errors from the above subject groups, composition andrndictation tests were administered. Then, the spelling errors obtained from the two testsrnwere listed under the subject groups who committed them (spelling errors).rnFor further analysis, spelling errors committed by trainees of Asella were classified intornfive major error types and were then, cross-checked with those errors committed byrntrainees ofDessie TTI as well as the teachers.rnThe results of the study, thus, indicate that most of the spelling errors (about 74.1%)rncommitted by trainees of Asella TTI were intralingual misspellings. Phonetic spellingsrnand errors of analogy with target-language spelling pattern were also found to be the mostrnrecurrent errors among the intralingual misspellings.rnIt was also found out that trainees of Asella TTI committed inter lingual spelling errorsrn(about 25.8%) in their writings. In this type of errors, errors of analogy with nativelanguagernspelling pattern were found dominant.rnThe data obtained from the teachers' writings, however, show fewer spelling errors bothrnin the composition and dictation as compared with the trainees' errors. In addition, it wasrnfound out that there were more spelling errors in the dictation than in the compositionrnwriting.rnOn the basis of the study and its results, major conclusions were drawn and pertinentrnrecommendations made.