According to Krashen, learners' anxiety, self-confidence, and stress can influence their learning. What is it about?

Krashen 的情感過濾假說（Affective Filter Hypothesis）主張，學習者的情感狀態（如焦慮、自信、動機）會形成一道過濾網，影響可理解輸入（comprehensible input）進入語言習得機制。低焦慮與高自信能降低過濾作用，促進語言習得。