How do I fix page text that is in the wrong language?

Choose your Website Language on the Language tab of Site Settings, then open Site Assistant, Site Review, Translation Cleanup. It scans editable page text and shows suggested translations into your website language. Accept the changes you want, then open each page draft to review and publish it. Accepting a cleanup suggestion does not change the live page.

Use the additional language settings when you want visitors to choose another language for the site.