一、 Don't worry. 别担心。（劝告对方别担忧）
a. — Is my illness serious? 我的病严重吗？
— Don't worry. You'll be well soon. 别担心，你很快就会好的。
b. — Can I pass the exam? 我能通过这次考试吗？
— Don't worry. I think you can. 别担心，我认为你能通过。
二、 Don't be afraid. 别担心。（劝告对方别担心）
a. — Will he agree to see me? 他会同意见我吗？
— Don't be afraid. 别担心。
b. — Will the exam be very difficult? 考试会很难吗？
— Don't be afraid. 别担心。
三、 It'll be OK/all right. 行，没问题。（使对方放心）
a. — Will my plan work? 我的计划会起作用吗？
— It'll be OK/all right. 没问题。
b. — Will the meeting succeed? 会议会成功吗？
— It'll be OK/all right. 没问题。
四、 It's all right. 没问题。（请对方宽心）
a. — Will you help me with my English? 你会帮助我学英语吗？
— It's all right. 没问题。
b. — Will the car pass the test? 汽车能通过检验吗？
— It's all right. 没问题。
五、 Well done! 干得不错！（肯定、鼓励对方工作）
a. — What do you think of my article ？你认为我的文章怎么样？
— Well done. 写得不错。
b. — Is my work OK? 我的工作还行吗？
— Well done. 干得不错。
六、 You can do it! 你肯定行！（肯定对方能力）
a. — I'm afraid I can't pass the exam. 恐怕这次考试我过不了关。
— You can do it! 你肯定行！
b. — I wonder whether I can finish the task in time. 我不知道是否能及时完成这项任务。
— You can do it! 你肯定行！
七、 Come on! 别灰心。（劝告对方别灰心）
a. — I'm afraid I can't succeed. 恐怕我难以成功。
— Come on! 别灰心。
b. — I'll not learn English any longer. I can't remember all these words. 我不想学英语了，我记不住这么多单词。
— Come on! 别灰心。
八、 That's better. Keep trying. 有长进，继续努力。（肯定对方的进步）
a. — What do you think of my homework? 你认为我的家庭作业做得怎么样？
— That's better. Keep trying. 有长进，继续努力。
b. — Is my composition still bad? 我的作文还是不好吗？
— That's better. Keep trying. 有长进，继续努力。
参考资料：http://bbs.fobshanghai.com/thread-1381782-1-1.html