Currently, the OBOD (orange bar of doom) which shows up whenever a user's talk page is modified, uses the following messages for the sentence:
MediaWiki:Youhavenewmessagesfromusers and Mediawiki:newmessageslinkplural
These messages essentially make it impossible to correctly translate MediaWiki:Youhavenewmessagesfromusers into hindi (and by extension, probably other grammatically similar north Indian languages).
The problem is caused by lack of plural support in MediaWiki:Youhavenewmessagesfromusers for $1, ie the number of messages received. The difference is basically equivalent to the english difference of is/are, with sentence structure in MediaWiki:Youhavenewmessagesfromusers needed to be modified based on the number of new messages, which isn't possible since the message doesn't support plural over $1 (as far as I know).
In my opinion, it would be best that these messages be joined into one message, seeing that neither is used elsewhere (the doc doesn't specify any other uses for the messages).