PHP: How do I change a variable dependent on another variable? (Newbie stuff)

I'm pretty new to webcoding and would like to improve a bit in php, but I'm already stuck :/

What I am trying to do is to have a sentence like
"Simon likes apples"
Now I have an input form for the name so I can choose the name. So it looks like
"$name likes apples"

<table>
    <tr>
        <td><input type="text" id="name1" name="name1"></td>
        <td><input type="submit" id="submit" name="submit" value="Apply"></td>
    </tr>
</table>
    </div>
    <div id="text">
    <?php
        if(isset($_REQUEST['submit'])) {
        $name1 = $_REQUEST['name1'];
        echo "$name1 likes apples.";
        }
    ?>
    </div>
</form>

Everything fine till now. Whatever name I type in replaces $name. Now what I want to do is to change the "likes" to "like" whenever i type in a pronoun (I, You, They etc.), which makes sense obviously. Now here is where I don't know what to do. My current code (which doesnt work) looks like this:

    <?php
        if(isset($_REQUEST['submit'])) {
        $name1 = $_REQUEST['name1'];
          if ($name1 = "I", "You") {
          $verb = "like";
          }
          else {
          $verb = "likes";
          }
        echo "$name1 $verb apples";
        }
    ?>

Also is there a way to make it non-capital sensitive?