import re


def add_hl_to_url(url):
    """ A function that adds or change language query to english for the given url. """
    # Note: Used it before is_playlist_url() or is_video_url().
    # Why we need this? For consistency when scraping the information embeded on the page.
    # Because youtube support different languages for the same page and it makes it hard
    # to scrap it if we will not force youtube to just send to us a specific page.
    return re.sub(r'&hl=[^&]+', '', url) + '&hl=en'