diff --git a/README.md b/README.md
index f28467a..e006c61 100644
--- a/README.md
+++ b/README.md
@@ -313,7 +313,7 @@ String
 ```
 
 ```python
-<bool> = <sub_str> in <str>                  # Checks if string contains a substring.
+<bool> = <sub_str> in <str>                  # Checks if string contains the substring.
 <bool> = <str>.startswith(<sub_str>)         # Pass tuple of strings for multiple options.
 <bool> = <str>.endswith(<sub_str>)           # Pass tuple of strings for multiple options.
 <int>  = <str>.find(<sub_str>)               # Returns start index of the first match or -1.
diff --git a/index.html b/index.html
index 5b7f119..ac1b3f2 100644
--- a/index.html
+++ b/index.html
@@ -299,7 +299,7 @@ Point(x=<span class="hljs-number">1</span>, y=<span class="hljs-number">2</span>
 &lt;list&gt; = &lt;str&gt;.splitlines(keepends=<span class="hljs-keyword">False</span>)    <span class="hljs-comment"># On [\n\r\f\v\x1c-\x1e\x85\u2028\u2029] and \r\n.</span>
 &lt;str&gt;  = &lt;str&gt;.join(&lt;coll_of_strings&gt;)       <span class="hljs-comment"># Joins elements using string as a separator.</span>
 </code></pre>
-<pre><code class="python language-python hljs">&lt;bool&gt; = &lt;sub_str&gt; <span class="hljs-keyword">in</span> &lt;str&gt;                  <span class="hljs-comment"># Checks if string contains a substring.</span>
+<pre><code class="python language-python hljs">&lt;bool&gt; = &lt;sub_str&gt; <span class="hljs-keyword">in</span> &lt;str&gt;                  <span class="hljs-comment"># Checks if string contains the substring.</span>
 &lt;bool&gt; = &lt;str&gt;.startswith(&lt;sub_str&gt;)         <span class="hljs-comment"># Pass tuple of strings for multiple options.</span>
 &lt;bool&gt; = &lt;str&gt;.endswith(&lt;sub_str&gt;)           <span class="hljs-comment"># Pass tuple of strings for multiple options.</span>
 &lt;int&gt;  = &lt;str&gt;.find(&lt;sub_str&gt;)               <span class="hljs-comment"># Returns start index of the first match or -1.</span>