Sometimes there is some article in one language in wikipedia, but there is no its equivalent in another language.
"Professional" wikipedians use templates that help to solve this - they use e.g. "Template:Interlanguage link" (https://en.wikipedia.org/wiki/Template:Interlanguage_link) that adds link to existing article in another language.

I think it would very useful to have this feature available to all users (not only experienced).

So, the proposal is:

• Add tab "Interlanguage link"
• Add language selector
• Add 2 input fields:
  1. the name of page in foreign language (existing link);
  2. the name of page in target language (red link)

If possible, it'd be better to do this without creating separate tab - just add the "Advanced" button to existing "Search pages" tab.

The name of template and how it is used must be customized by wikipedia administrators.