Aside: PayPal Default Merchant Language Settings

Note to self. If your PayPal button is directing your visitors to a non-English website (probably because your account was set up in a different country) you can override the language setting with an lc key in the PayPal button form, like this:

<input type="hidden" name="lc" value="US" />

This will make sure that the checkout page is in English. Read more about HTML Variables for Website Payments Standard.