无论何时,无论何地,只要你需要我,我就会永远陪在你身边用英语怎么说

No matter where, no matter when（可以倒过来说）, if you need me, (then) I will always be by your side.
或
No matter where, no matter when（可以倒过来说）, as long as you need me, (then) I will always be by your side.
像whenever ， wherever 也可以用， 但是不提倡。