How to respond to student writing and speaking: fossilized errors.

We will examine how to respond to the writing/speaking of heritage learners/speakers and what ways of error corrections should be implemented to their writing and their speaking, focusing on the fossilized errors
Teacher feedback may represent a big investment of time by instructors and students highly value it, but the question is: what types of errors should us teachers respond to? When should we respond to them? What are the most efficacious ways of responding to them? And what role must error treatment (corrective feedback) play in the teaching of the process of writing and speaking?