Abstract The use of machine translation (MT) systems by undergraduate and postgraduate students has been analysed in different studies (Sycz-Opoń and Gałuskina 2017; Jia et al. 2019; Loock and Léchauguette 2021, to mention a few). An analysis of the German-into-Basque translation of multi-word expressions (Sanz-Villar 2024) observed that students’ dependence on MT systems was very high; i.e., traces of the MT proposals were found in the outputs of translation trainees. To specifically analyse the impact of MT proposals on students’ translations, two tasks were designed in 2021 in which nine students participated. Both tasks consisted of translating an excerpt of a children’s literary text from German into Basque. The first translation task was done with the aid of MT tools and the second was a from-scratch translation where the use of MT systems was not allowed. The goal of the present study is to compare the results of both tasks, focusing on the translation of phraseological units (PUs) to observe the features of students’ translations accomplished with and without the aid of MT tools. Since students used MT outputs during the first translation task, machine-translated texts are also compared to human-translated ones. The results show that the tendency to retain the phraseological character of the original text is stronger in professional translations than in machine-translated texts. In general, reliance on MT system outputs when translating PUs is quite strong among trainee translators. When comparing the results of the two tasks, it was observed that for some students, the number of techniques used to maintain the phraseological level of the original text increased in the translation done without MT. Interestingly, examples of creative translations were found in the translations done without the aid of MT tools.