2.The Causes of Errors and Mistakes Errors-usually arise from the learner's lack of knowledge;it represents a lack of competence. Mistakes-often occur when learner's fail to perform their competence.In other words,the learner's has already learned the knowledge or skill but simply fails to function correctly due to lack of attention or other factors (The change of ideas,exhaustion.nerveusacss,cold, distraction .etc) E.G.:Jeff/诺丁山2. The Causes of Errors and Mistakes Errors—usually arise from the learner’s lack of knowledge; it represents a lack of competence. Mistakes—often occur when learner’s fail to perform their competence. In other words, the learner’s has already learned the knowledge or skill but simply fails to function correctly due to lack of attention or other factors. (The change of ideas，exhaustion，nervousness，cold， distraction .etc) E.G.: Jeff / 诺丁山