Exact meaning and use of一下子 My textbook says 'in a short while' but I've also heard that it's more like 'in one go', and that there is an element of surprise and unexpectedness. What exactly does 一下子mean and how do I use it?

非...不可 My textbook has an exercise with the following sentence: 今天晚上我就是不睡觉也要把作业写完. I'm supposed to rewrite this using 非...不可, but I'm not even sure what the original sentence means. Can anyone help me?

What exactly is the difference between 羡慕, 嫉妒 and 佩服 I know they are all in the realm of admiration/envy/jealousy, but when do I use which?

How do I use 做出.......的样子? Can someone please give me some example sentences? I understand that the meaning is supposed to be similar to 假装, but how can I use it?