 
   ## Configuring the shell
 
-  There is a number of customization options provided by the shell. Take a look
+  There are a number of customization options provided by the shell. Take a look
   at the docs for the `IEx.Options` module.
 
   The main functions there are `IEx.Options.get/1` and `IEx.Options.set/2`. One


  ## The Break command

  Inside IEx, hitting Ctrl+C will open up the BREAK menu. In this
  menu you can quit the shell, see process and ets tables information
  and much more.

  ## The User Switch command

  Besides the break command, one can type Ctrl+G to get to the
  user switch command menu. When reached, you can type `h` to
  get more information.

  In this menu, developers are able to start new shells and
  alternate in between them. Let's give it a try:

      User switch command
       --> s 'Elixir.IEx'
       --> c

  The command above will start a new shell and connect to it.
  Create a new variable called hello and assign some value to it:

      hello = :world


  This means that any benchmarking done in the shell is going to have
  skewed results. So never run any profiling nor benchmarks in the shell.

  Second of all, IEx allows you to break an expression into many lines,
  since this is common in Elixir. For example:

      iex(1)> "ab
