Locative case marking and adverbs

[mallu]

In Malayalam( An Indic Language) a noun marked with locative case marker can act as an adverb. for  eg.  vegath-il  ( speed in)- speedly. Is there any other language that employs this strategy ?
       Speed .LOC
 Pl. help

[Daniel]

Probably, but I can't think of any examples. I'll keep an eye out in case I happen to see this in any grammars I'm looking at. It seems plausible.

Is this the only [productive] adverb-forming strategy in Malayalam?

I believe some languages use the "with" case (probably instrumental, maybe also sometimes comitative).
In Romance languages, adjectives are formed with what was the ablative case for the phrase "with a [ADJ] mind" as in "rápidamente" lit. 'with a fast mind' = 'quickly'.

[vox]

Hi mallu
When someone says 'to sing in unison’ or 'to speak in public’ don't 'in unison’ and ‘in public’ function as adverbs ? I think that ‘in public’ could be replaced by ‘publicly’ but I’m not an english native speaker.

[Audiendus]

Also:

English: indeed (in fact, in truth. truly)
French: enfin (finally)
Latin: vero (truly – ablative case of verus)

[Daniel]

Turkish (data from the grammar by Göksel & Kerslake, 2005: variously, between pages 196-208) uses the locative case for temporal adverbs, locational adverbs (like 'at home' and 'downstairs'). Since Turkish has a lot of productive use of case marking it is relevant to compare, but the types used seem to be what you'd expect for locative functions ('at a time', 'in a season', etc., and actual locations).