Having learned about second language acquisition theories, now I can reflect about my experience of an ESL (English as a second language) student and teacher. The input, interaction and output theory, for example, made me think about the negotiation processes for acquiring meaning. I realized that, as a teacher, sometimes I don’t use these processes as much as I could – and if I did that, my students’ learning would probably improve. Last class, when we discussed about some hypothetical situations involving SLA, we agreed that input is extremely necessary – every single theory considers it an important part of acquisition. In this sense, I believe my experience as an English student was very positive: my teachers used to advise me to watch movies, listen to music and read books in English. I learned a lot from that – even more than what I learned in class, I dare to say. The Monitor Theory explained things I had always believed to be true – although I couldn’t explain why or how it happened. The Monitor hypothesis, which is a part of the Monitor Theory, says that second language speakers monitor their production all the time. I think it always happens to me: I’m always asking myself “are you sure this is correct?”, “what’s the best way to say that?”, etc. In conclusion, this module of Applied Linguistics was very important to me, since it gave me theoretical support for my practices as a teacher and also as a student. In addition to that, I was able to reflect about my actions and try to improve them.