So how important is it to display in the HTML code, the language of the site, if you already declared it in Google Search Console.
JOHN MEULLER (Webmaster Analyst from Google):
We don’t use that at all.So we use the hreflang links if you have that if you have different language versions.But the language attribute within the HTML markup is something we don’t use at all. We’ve found that this language markup is something that is almost always wrong. So we tend to ignore that.