I operate an English website handling multilingual content (up to 13 other languages), with a large amount—but not all—of our content translated into those other languages. We use rel="alternate" to link to those other pages which presents 2 scenarios:
- Translation exists: show translated article.
- Translation doesn't exist: show original article, with short placeholder text (i.e. "this is not yet translated").
My question is would we run into duplicate content issues, and be penalised for it, if we use rel="alternate" to link to such untranslated content, even if exists on a different language subdomain (specified in the alternate link)?