diff --git a/README.md b/README.md
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+++ b/README.md
@@ -128,8 +128,8 @@ Set
 ```
 
 ### Frozen Set
-* **Frozen set is immutable and hashable set.**
-* **It can be used as a key in a dictionary or as an element in a set.**
+* **Is immutable and hashable.**
+* **That means it can be used as a key in a dictionary or as an element in a set.**
 ```python
 <frozenset> = frozenset(<collection>)
 ```
@@ -137,7 +137,7 @@ Set
 
 Tuple
 -----
-**Tuple is immutable and hashable list.**
+**Tuple is an immutable and hashable list.**
 ```python
 <tuple> = ()
 <tuple> = (<el>, )
@@ -145,7 +145,7 @@ Tuple
 ```
 
 ### Named Tuple
-**Named tuple is tuple's subclass with named elements.**
+**Tuple's subclass with named elements.**
 
 ```python
 >>> from collections import namedtuple
diff --git a/index.html b/index.html
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@@ -288,19 +288,19 @@ Counter({<span class="hljs-string">'blue'</span>: <span class="hljs-number">3</s
 </code></pre>
 <h3 id="frozenset">Frozen Set</h3>
 <ul>
-<li><strong>Frozen set is immutable and hashable set.</strong></li>
-<li><strong>It can be used as a key in a dictionary or as an element in a set.</strong></li>
+<li><strong>Is immutable and hashable.</strong></li>
+<li><strong>That means it can be used as a key in a dictionary or as an element in a set.</strong></li>
 </ul>
 <pre><code class="python language-python hljs">&lt;frozenset&gt; = frozenset(&lt;collection&gt;)
 </code></pre>
 <h2 id="tuple"><a href="#tuple" name="tuple">#</a>Tuple</h2>
-<p><strong>Tuple is immutable and hashable list.</strong></p>
+<p><strong>Tuple is an immutable and hashable list.</strong></p>
 <pre><code class="python language-python hljs">&lt;tuple&gt; = ()
 &lt;tuple&gt; = (&lt;el&gt;, )
 &lt;tuple&gt; = (&lt;el_1&gt;, &lt;el_2&gt;, ...)
 </code></pre>
 <h3 id="namedtuple">Named Tuple</h3>
-<p><strong>Named tuple is tuple's subclass with named elements.</strong></p>
+<p><strong>Tuple's subclass with named elements.</strong></p>
 <pre><code class="python language-python hljs"><span class="hljs-meta">&gt;&gt;&gt; </span><span class="hljs-keyword">from</span> collections <span class="hljs-keyword">import</span> namedtuple
 <span class="hljs-meta">&gt;&gt;&gt; </span>Point = namedtuple(<span class="hljs-string">'Point'</span>, <span class="hljs-string">'x y'</span>)
 <span class="hljs-meta">&gt;&gt;&gt; </span>p = Point(<span class="hljs-number">1</span>, y=<span class="hljs-number">2</span>)