The purpose of this study is basically to identify thornlanguage f'unc'bi.ons most commonlyused by junior secondary schoolrnteachers of English in the classroom. In addition, the study aimsrnat identifying the linguistic errors that occur in the languagernfunctions and along with this it attempts to show which languagernfunctions the teachers find most difficult to handle and whioh theyrnmani.pul.a+e with ease.rnFour government junior second8~y schools were selected forrnthe study. From tho twelve teachers of English working in thesernschools eight were selected and recorded while teaching English inrntho classroom. The reoorded lessons were then transcribed andrnanalysed on the basis of the system of analysis developed byrnSinclair and Coulthard (1915) vri..tha slight modification made byrnthis researcher.rnThe results of the analysis of the findings showed that thernmosf commonLanguage functions used by these teaohers wore:rna) Asking questions (Elioiting and Re-elioiting) whioh tookrn59.3% of the lesson time;rnb) Ex:plaining, Exempl.i.f'yi.ng, summarizing (Informing in general)rnwhich took' 26.1% of the lesson time;rnc) Giving instructions and orders (Directing) whioh took 9.3%rnof the lesson time;rnd) Opening and olosing the stages of tho lesson (Framing andrnFocusing) which took 4.57~of the lesson time; andrne) Checking students' understandine of the Leason which tookrn0.8% of the lesson time.rn-111-rnThe results also showed that there wor-e511 errorsrn(granunatical and pronunciation errors) which woro classified into 11rncategories. Of theso errors, 39.5~~ were identified in Elicits, 36.4%rnin Informs, 14.2% in Directs, 6.6% in Boundary exchanges, and 3.3% ':rnin Checks. Further, it was fotmd that the ratio of errors tornexchanges is much greater in Informs than in anyone of the otherrnexchanges. There were nearly three more errors in every Informrnexchange than in everyone of the ollher exchanges.rnIn addition, the results showed that the functions ofrnexplaining, summarizing, evaluating (in general explaining meaningrnor putting over information) and giving instructions were the mostrndifficult ones for the teachers to hanclle while asking questionsrn(particularly re-eliciting by nominating or prompting or looping)rnand ohecki.ng students' understanding wer-ethe onos tho teachersrnfOlli~deasy to manipulate.rnOn the basis of the findings it was recommendedthat juniorrnsecondary school teachers of English need to be given appropriaterntraining in these language f'uno'bi.onsparticularly in the functionsrnconcerned with explaining meaning or putting over information,rnrephrasing and simplifying unanswer-ed elicits, and givingrninstructions. In addi,ti011tit was recomended that improvementsrnshould be made in the textbooks in a way that would minimizernteachers' over-reliance on them and proviae enough chanoes of usingrnthese language f'unctions as frequently and meaningfully as possible.