I am working for multi lingual websites under one brand.
English Language: www.example.com (Root domain)
Polish Language: pl.example.com (Sub domain)
Danish Language: dk.example.com (Sub domain)
German Language: de.example.com (Sub domain)
If Google will penalize main English domain for any of penalty including Panda, Penguin, Algorithmic, Manual penalty, Unnatural backlink penalty, and in that case main English domain will be suffered accordingly. But is it going to make any difference for sub domains as well?
It would be great if you specify the effects of each penalty on sub domains, if any.
P.S : All sites contain different content, different D class IP, and cross domain links are tagged with Nofollow.