I signed up today for a conference in Spain. They are using PayPal for taking registration. I’m trying to avoid PayPal, but as the only alternative (bank transfer) is a real pain to do from Japan, I bite the bullet when the other party only offers PayPal as a sensible option. So, I was directed to a PayPal site to process the payment, having given them all the registration details they demanded (including them requiring a landline phone number! I just re-entered my mobile number, which they had already also required). The initial PayPal page was all in Spanish. There was no visible button for changing the language. An understandable (to me) bit asked for my country, so I selected Japan and the page renewed into English. Odd, but useful to me. So, I gave them my credit card details including the billing address and submitted them. The “review and confirm payment” page then came up in Japanese. These days I know enough Japanese to have been able to figure this one out.
So, PayPal displayed itself in three different languages during one transaction, with at no point that I could see a visible button to select a language I can definitely use, and with some apparently random selections of which language to display a particular page in. This is not good internationalisation.