Your site can open in Spanish and still offer English
Settings → The Basics now asks for your Site Language, the language your site opens in, and has an Also Offer box for each other language. A site can open in Spanish with an English switch, as well as open in English with a Spanish one, or use one language alone. A member or visitor with no saved language gets your Site Language in their emails, and announcements are written in it too. A member’s language choice is saved to their account only when they switch, so a phone left in one language no longer changes what they picked on another device.