Update grammar

en/functions/index.html

@@ -197,7 +197,7 @@ <h1>Python Functions</h1>
 
 <h2> Anatomy of a Function</h2>
 
-<p>To understand how to defined functions which can take in data and can return data, let's disect a simple example of the definition of an average function. Average takes in two pieces of data and returns the mathematical average.</p>
+<p>To understand how to define functions which can take in data and can return data, let's disect a simple example of the definition of an average function. Average takes in two pieces of data and returns the mathematical average.</p>
 
 <p><b>Definition</b>: The definition of average specifies that it needs to pieces of information by writing two variable names, separated by a comma <code>,</code> between the parenthesis in the definition line. In the body of the average function it can assume that the function call provided two pieces of information inside the function body average can refer to the first piece of information as variable <code>a</code> and the second as variable <code>b</code>. The definition of average specifies that it gives information back to ther caller via the line that starts with <code>return</code>.</p>
 
@@ -849,4 +849,4 @@ <h2>Runnable lucky_sum - Autograde Table</h2>
     });
 </script></body>
 
-</html>
+</html>