Vivanco, Margot. β€œTo Be or Not to Be an Auxiliary Verb. The Case of Spanish <Poner(se) a + infinitive&gt;”. Borealis – An International Journal of Hispanic Linguistics 8, no. 1 (June 1, 2019): 35-54. Accessed February 21, 2020. https://septentrio.uit.no/index.php/borealis/article/view/4655.