If you are using a desktop browser, the language (and currency) you see depends upon the site you are signed into. The emails you get will likely be in the language of your site of registration.
To see eBay in English, try ebay.com ($), ebay.ca (C$), ebay.co.uk (Pounds), ebay.ie (Euros) or ebay.com.au (AU$).
If you are using the eBay app, what you see may depend on whether you have the app set to detect your location or if you have it set for a particular country. Your actual location may override some settings, though, I am not certain about that.
