Abstract or things to thank for

Question

Hi, in this example: Elle vous remercie pour toute votre aide - I would think of "de" instead of "pour" as it does look to me as an abstract noun. There's no context and we can think of moral aid as well, which is clearly abstract. How to choose in similar cases? Merci en avance!

Accepted Answer

You can use (re)merci with either pour or de with abstract nouns. (Re)merci pour is the only expression for standard use with nouns for physical things. Therefore either is fine with “aide”. 
As pour can be used with any noun, it is a safer bet for non-native speakers (we don’t want to ‘merci du cadeau’ by accident). If you’re confident, you can use de with abstract nouns and reserve pour for “physical “ nouns.
The usage is different with infinitives where merci de is required. 
So, pour works for all nouns, de works with infinitives including the infinitif passé.