现在完成进行时
现在完成进行时的构成
重要程度：8 分
<h2>现在完成进行时的构成</h2>
<p>现在完成进行时由 "has/have been + 动词-ing 形式" 构成。</p>
<ul>
<li>肯定句：主语 + has/have been + 动词-ing + 其他成分</li>
<li>否定句：主语 + has/have not been + 动词-ing + 其他成分</li>
<li>疑问句：Has/Have + 主语 + been + 动词-ing + 其他成分？</li>
</ul>
<h3>举例说明</h3>
<ul>
<li>肯定句：She has been studying English for two hours.</li>
<li>否定句：They have not been playing football since morning.</li>
<li>疑问句：Have you been waiting for the bus?</li>
</ul>