Google needs a bit of help to detect your website’s localized language versions. To do this correctly, you need to be aware of the hreflang attribute and how to use it.
Let’s now assume that you have ordered professional translations from Get Localization for your site from English to Spanish. You define an alternative version of your site using the link tag and hreflang attribute like this in your English website:
<link rel="alternate" hreflang="es" href="http://es.example.com/" />
This means that your Spanish website will be found at http://es.example.com. But now, hold on! This is not the whole story, and some precautionary measures should be taken to do this correctly.
First and foremost, make sure that Google Search Console is tracking your website property (https://www.google.com/webmasters/). This is important as it lets you see whether your hreflang tags and international targeting are working properly.
Furthermore, you need to use these tags correctly – if you just go and add hreflang tags into your site, I bet your Search Console will show “Hreflang Tags with Errors”.
Most common hreflang error is “No return tags”. This happens because your English page links to Spanish page, but your Spanish page does not link back to your English page. Why must it do that? Well, Google uses this to verify that the content really is an alternative version of your site.
So, you also need to add this tag into your Spanish page:
<link rel="alternate" hreflang="en" href="http://www.example.com/" />
After this you’re good to go. Google will now process your site. However, it will take some time. Google’s indexing is otherwise fast, but not so much for international content.