被动语态
被动语态的基本概念
重要程度：8 分
<div>
<h2>被动语态的基本概念</h2>
<p>被动语态是用来表示动作承受者的一种语态。在被动语态中，主语是动作的承受者，而不是执行者。</p>
<h3>构成形式</h3>
<p>被动语态通常由“助动词be + 过去分词”构成。</p>
<ul>
<li>一般现在时：am/is/are + 过去分词</li>
<li>一般过去时：was/were + 过去分词</li>
<li>现在完成时：have/has been + 过去分词</li>
<li>情态动词：情态动词 + be + 过去分词</li>
</ul>
<h3>举例说明</h3>
<p>主动语态：Tom writes a letter.</p>
<p>被动语态：A letter is written by Tom.</p>
<p>在这个例子中，主动语态中Tom是写信的人，而在被动语态中，主语变成了“一封信”，即动作的承受者。</p>
<h4>例题</h4>
<p>将以下句子从主动语态改写为被动语态：</p>
<ol>
<li>They built a new school last year.</li>
<li>The teacher gave us some homework yesterday.</li>
</ol>
<p>答案：</p>
<ol>
<li>A new school was built by them last year.</li>
<li>We were given some homework by the teacher yesterday.</li>
</ol>
</div>