count_words_in_string.php

<?php 

function count_words($needed_word, $string)
{
    $words       = str_word_count($string, 1);
    $words_count = array_count_values($words);
    
    // Use multibyte string to lower 
    return $words_count[mb_strtolower($needed_word)];
}

/*
 * Example: count_words("email", "I've got an Email , 1 email was from my daddy !");
*/