This study is at the crossroads of Natural Language Processing (NLP) and Second Language Acquistion (SLA). We used Whisper's speech recognition on a French L2 learner corpus to get automatic transcripts, and compared them with pre-existing manual transcripts. We then conducted quantitative and qualitative analysis of the issues which are inherent to the specificities of interlanguage for any automatic tool. We will discuss the different issues encountered by Whisper that are specific to learner corpora.