This research article presents the results of an exploratory study that was conducted with a group of 14 early childhood education pre-service teachers at a private Colombian university. It intended to determine: 1) The amount of metalanguage expressions used for the teaching of English as a Foreign Language (EFL) and used for the teaching of contents in FL. 2) The amount of concepts related to the previous topics pre-service teachers were able to learn in a 7-session (14 face-to-face hours) course based on a methodology inspired by the approach of Content and Language Integrated learning (CLIL), using songs, rhymes, and poems in English to young children. 3) The degree of difficulty the pre-service teachers perceived about teaching English and contents in English to young children. The study is quasi experimental because it was performed with pre-study and post-study tests of only one group, and it is quantitative because only quantitative data were analyzed using a non-parametric statistical hypothesis test and a non-parametric measure of rank correlation. The pre-service teachers were found to successfully learn vocabulary and concepts, but their perceptions about the degree of difficulty of teaching English as a Foreign Language and contents in a Foreign Language remained basically the same as they were before the course started. Besides, the correlation between the participants’ level of English and their learning process was analyzed, as well as the correlation between their level of English and their perceptions about the degree of difficulty of teaching EFL and contents in FL. The results show a strong correlation in the first case; but no correlation for the second one.