The main aim of this paper has been to examine if Swedish students at upper secondary school were able to use the morphemes The progressive –ing, The irregular past and The irregular third person. In addition, it has also addressed if the students examined in this essay were able to use some morphemes better than others. In addition, it concluded if the results found in this paper were in accordance with what other researchers have concluded. The paper is based on essays written by students at upper secondary school that can be found in The Uppsala Learner English Corpus, as well as essays written for the national test by students studying English 6. In the course of the study, it was vital to explain what the natural order actually is as well as what researchers who believe in it claim and what researchers who do not believe in it claim. Consequently, it becomes important to clarify the differences between a cross-sectional study and a longitudinal study. When analysing the essays the program Antconc was used. It is a free corpus analysis program that allows researchers to study several texts at once. Next, to determine if the students had acquired the morphemes, all obligatory contexts where the morphemes should be used were analysed manually. What can be concluded from this paper is that the three morphemes have not been acquired by the students who were examined in this paper. Students could use some forms of the morphemes; however, even in those cases the correct usage in percentage of the morpheme were often not above 85%. These results were quite like the ones found in studies conducted on students at secondary school; this indicates that students at both secondary and upper secondary school do not actually acquire these morphemes fully. What they do acquire are different forms of a specific morpheme that they probably use quite a lot in their writing. / Syftet med denna uppsats har varit att undersöka om svenska elever som studerar på gymnasieskolan kunde aktivt använda de engelska morfemen The progressive –ing, The irregular past och The irregular third person. Dessutom har uppsatsen också behandlat om det fanns morfemen som eleverna kunde använda sig bättre av. Den har även jämfört sitt resultat med vad andra forskare har hittat. Uppsatsen är bygd på essäer skrivna av elever på gymnasieskolan som finns att hämta i The Uppsala Learner English Corpus. Dessutom använder den sig av essäer skrivna av elever för det nationella provet i engelska 6. Under studiens gång var det viktigt att förklara vad The natural order är liksom vad forskare säger gällande denna teori. Följaktligen blir det viktigt att klargöra skillnaden mellan en tvärsnittsstudie och en longitudinell studie. Vid analysen av essäerna användes programmet Antconc. Det är ett gratis korpusanalysprogram som tillåter forskare att studera flera texter samtidigt. För att klargöra om eleverna hade förvärvat morfemen var det därefter viktigt att studera alla obligatoriska sammanhang där morfemen måste användas, vilket gjordes manuellt. Det som framgår är att eleverna som granskades i studien inte har förvärvat de tre morfemen. Eleverna kunde använda sig av vissa former av varje morfem, men även i dessa fall var den korrekta användningen i procent oftast inte mer än 85%. Detta resultat var ganska likt de studier som har granskat elever i högstadiet, vilket tyder på att elever i både högstadiet och gymnasiet inte förvärvar dessa morfem fullt ut. I de flesta fall kunde eleverna enbart använda olika former av morfemen.