<?php

    $string = "One two three four five six seven eight nine ten.";
    
    // the first number words to extract
    $n = 2;
    
    // extract the words
    $words = explode(" ", $string);

    for($i=0; $i<=$n-1; $i++) {
      $firstCount[] = ' ' .$words[$i];  // This will return one, two
    }
   
    for($i =$n; $i<count($words); $i++) {
      $lastCount[] = ' ' . $words[$i];  // This will return three four five six seven eight nine ten
    }
    
    print_r($firstCount);
    print_r($lastCount);