How to add checkbox in Profile Page

Hi,
I liked to customize my profile page by adding new fields to get more info from the user like “Gender” or “Speaking Languages”. I managed to get the text input and radio button input to work, the problem I having now is on the checkbox type of input. Here is my code:

function my_user_field( $user ) {

    $language = get_the_author_meta( 'language', $user->ID);

?>
    <h3><?php _e('More About You'); ?></h3>
    <table class="form-table">

          <tr>
            <th>
                <label for="language"><?php _e('Language'); ?>
            </label></th>
            <td><input type="checkbox" name="language" <?php if ($english == 'yes' ) { ?>checked="checked"<?php }?> value="yes" /> English<br />
                <input type="checkbox" name="language" <?php if ($mandarin == 'yes' ) { ?>checked="checked"<?php }?> value="yes" /> Mandarin<br />
            </td>
        </tr>
    </table>
<?php
}

function my_save_custom_user_profile_fields( $user_id ) {
    if ( !current_user_can( 'edit_user', $user_id ) )
        return FALSE;
     update_usermeta( $user_id, 'language', $_POST['language'] );

}
add_action( 'show_user_profile', 'my_user_field' );
add_action( 'edit_user_profile', 'my_user_field' );
add_action( 'personal_options_update', 'my_save_custom_user_profile_fields' );
add_action( 'edit_user_profile_update', 'my_save_custom_user_profile_fields' );

The checkbox options are not mutually exclusive, they are multi select enable.

I wondering using array for language[], but I can’t make it right. Help please. Thanks