高考英语语法：英语句子副词用法说明
1. 句子副词的特点
句子副词用于修饰句子(而不是修饰某个单词)，反映说话人的观点和看法，如 actually, certainly, clearly, definitely, evidently, fortunately, frankly, honestly, luckily, obviously, perhaps, possibly, probably, surely, undoubtedly, unexpectedly 等。
2. 句子副词在句中的位置
句子副词通常位于句首(或分句句首)：
Obviously he can’t tell the difference between them. 显然他无法区别两者的不同。
I arrived late but luckily the meeting had been delayed. 我迟到了，幸而会议推迟了。
但有些句子副词也可以出现在句中：
He smiled nastily. He evidently knew something I didn’t. 他发出狞笑，他显然知道一些我所不知道的事。
3. 句子副词与其他副词的用法比较
有的句子副词也可用作其他种类的副词，不过这往往会导致位置和语义的变化：
Clearly he didn’t say so. 显然他没有这样说。(句子副词)
He didn’t say so clearly. 他说得没有那么清楚。(方式副词)
Frankly, you are wrong. 说实在的，你错了。(句子副词)
He spoke frankly about his past life. 他坦率地谈了他过去的生活。(方式副词)