Go with straight text and no .. or / unless they are referring to pages inside a different directory. As long as that is the page your domain points to then you're set to go. So if all of your site pages are in the main root directory of your site then go with:
"english/index.html"
The dots and slashes usually represent directory structure so when you use:
../
That means go up one directory and then find the files represented in the path.
IF there is no reason for the "english" directory, other than to give the pages a place to be, then you should move those pages to the Root directory of your domain (public_html in most cases) to keep the process simple. The only time people really need to move the actual web HTML pages to a directory is to organize them. I'll assume you have them in multiple languages since the directory is called "english", but if that's not the case and it's not organizing them, then it would be easiest to move them to the main directory of the site and reference them without the "english" in the pathway. Obviously if they are organized, just ignore this part of the advice