Translate the page body and essential navigation, and provide links that let users choose a language. Do not label an untranslated body as a different language version.
hreflang identifies corresponding language or regional versions. HTML, HTTP headers and sitemaps are alternative implementation methods; a separate sitemap for each language is not a universal requirement.
Check content, metadata, internal links and canonical URLs for each language. Forced redirects based only on IP address or browser language can obstruct access to some versions, so verify direct access to each URL.