don,t walk on the grass,will you.
再问： 为什么
再答： 当陈述部分是祈使句时，疑问句要根据语气来表达，分三种情况：
1）一般情况下用will you 或won't you。
Give me a hand, will you?
Leave all the things as they are, won’t you?
2)以Let's（听者包括在内）开头的祈使句，前肯后可肯可否，疑问句必须用shall we（shall只用于第一人称）;只有以Let us（听话人不被包括在“us”里面）或Let me开头的祈使句，问句才用will you。
Let us know the time of your arrival, will you?
Let's try again, shall we?
Let me help you, will you?
Let’s have a look on your book，shall we？
3)当陈述句是否定的祈使句时，问句可用will you 或can you 。
e.g. don’t make much noise, will/can you?
