Best Solution: Try a different Browser.
This foreign language problem sometimes occurs at Paypal – we are not sure why but usually an English language link will be given at the bottom of the Paypal screen even if most of the page is in a language other than English.
One possible answer is that the last time you purchased at Paypal you were sent to a non English version of Paypal and that link or cookie has stuck in your cache. Clearing the cache might resolve that issue.
Alternatively please try a different browser.