A comparable corpus is a corpus consisting of texts from the same domain in more languages. In contrast to a parallel corpus, the texts are not translations of each other and belong to the same domain with the same metadata. An example of a comparable corpus is corpus made from Wikipedia.
A collection of texts produced by learners of a language used to study errors and mistakes made by learners of languages. Learner corpora in Sketch Engine can use both error and correction annotation. A special search interface is available to search by the former or the latter or both.
see also Setting up a learner corpus
A parallel corpus is a corpus consisting of the same text in two languages. The texts are aligned (matching segments, usually sentences are linked). The corpus allows searches in one or both languages to look up translations.