Olá, I'm writing a 'carta de apresentação', applying for a job as a teacher. I want to say: "Although initially my role was to simply assist my colleagues while they taught classes, by the end of my employment I had been given many important responsibilities and I was carrying out the same duties as an actual teacher". "Ainda que, inicialmente, a minha função era simplesmente ajudar aos meus colegas enquanto ensinavam clases, no final do meu emprego, deram-me muitas responsabilidades importantes e desempenava os mesmos deveres que uma professora atual". Is this right? And is the register formal enough for a job application letter? Obrigada!