This paper is an introduction to COMPARA and to how it can be used in language learning and translation training. COMPARA is a machine-readable and searchable collection of Portuguese-English and English-Portuguese source texts and translations. The main characteristics of COMPARA are that it is open-ended, freely available on the Web, and made for people who have never used corpora before as well as for experienced corpus users. COMPARA is encoded according to the IMS Corpus Workbench system, developed at the University of Stuttgart, and is distributed on the WWW via the DISPARA interface, developed by the Computational Processing of Portuguese project.