1. Is translated content treated as duplicate content?
No, unless you just translated it using Google Translate. Auto-generated translations might be considered as spam.
2. Is the same content posted on different TLDs treated as duplicate content?
If you use different ccTLDs and have hreflang tag in place then you do not have duplicate content issues.
3. Can I use the same metadata on two or three pages in the same language but targeting different countries?
Yes, you can, but before you do so make sure you implement hreflang tag first.
4. What is hreflang rel='alternate'?
hreflang tag is a useful tag which allows Google to understand which country you are targeting, you may have for example 3 pages in German: one for Germany, the second for Austria and the third one for Switzerland if all have the same content in German you do have duplicated content issues unless you place the hreflang tag which specifies geo and language location for each of them.
5. Where do we have to place hreflang tag?
hreflang tag needs to be placed on every single page on a domain, not only on the home page!
6. Is there any situation when using hreflang tag is impossible/not advised?
Yes, when the implementation of the tag is not manageable so on huge websites/blogs where placing the tag will require loads of time and money to code...
7. What are the most important factors which Google uses to determine correct geo-targeting?
- local domains or ccTLDs
- Google Webmaster Tools
- local server
- Sitemap, hreflang tag and canonical tags
- currency and address format
- inbound links
8. hreflang and canonical tag, should you use both tags on the same page?
Having the same content for multiple countries with hreflang tag implemented on every page retrospectively resoles duplicate content issues. Especially if you localise content as much as possible and serve it on unique URLs for each of these countries. In these cases it is best not to use the canonical tag. As Dejan SEO says: The only situation when you will have to use the canonical tag would be if there are duplicated content issues on the same domain (duplicated articles or products).
It’s best to utilise rel=”canonical” if the two pages are truly the same thing. If there are differences, even subtle, which may be relevant to region/language then it’s best not to canonisalise it in order to help Google serve the best content to the right type of audience.
The only situation when you will have to use the canonical tag would be if there are duplicated content issues on the same domain (duplicated articles or products).
9. Are auto-redirects based on the IP address or headers language good?
Google recommends avoiding them:
'Avoid automatic redirection based on the user's perceived language. These redirections could prevent users (and search engines) from viewing all the versions of your site'
10.When creating international pages would you go for subdomain or subfolder, why?
From SEO prospective creating new pages on local ccTLD is the best solution, if however for some reason this is out of question create your international pages as subfolders not subdomains. This way the authority of your main page will be passed over onto your foreign sites.
Read more about developing international SEO sucessfully.