1. Interlingual errors are those the source of which is the mother tongue. These errors reflect the inference of L1 in L2 acquisition. Developmental errors manifest the natural processes of language learning. These errors reflect the universal aspect of language learning; i. e. if you want to learn a new language, you have to commit errors.
2. Errors which do not block the communication (local errors) should not be corrected at once. Sometimes, students can correct their errors if they reproduce their utterances again. So, here, we should not correct their errors when we are aware of their ability to self-correct.
Global errors should be corrected in a way that the students do not get ashamed.
3. Having knowledge of the type of errors, we can decide how to deal with them, whether or not to correct them, how much explanation we should present.