在祈使句中，我们通常用 please 开头一个句子。如：

Please come in.

Please wait a moment.

Please tell me what you know.

Please help me with the heavy box.

但是，如果是一个疑问句也可以用 please 开头吗？比如：

Please can you do it for me?

Please can you tell me the news?

——参考：

Wordorder

We usually put please at the end of a request with could, can and would, but we can also put it at the beginning or in the middle. Please in the mid position makes the request stronger.

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When talking to adults, children often use please in front position to adults when making a request or asking for permission.

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上文来自《剑桥在线英语词典》关于 please 与情态动词连用时的位置及使用注意事项的详细解析，最常见的是位于句末，位句首及句中时语气较强，尤其是为句中时，有时含有命令语气，因此相比较而言不那么有礼貌，使用范围也相较于其他两种位置较窄。由于上文语言简单易懂，就不给大家翻译了。