I was pretty sure that he would support me for changing the age-old and static structure of our organisation.
My book says it should be in instead of for, is it correct ? To my ears for sounds well.
Please don't vote this to close / duplicate, there are numerous threads on SE similar to this but I couldn't find any one which could clear my doubt.
Best Answer
The noun support takes complements with for, designating what is supported.
But the verb support is transitive: what is supported is designated by an object:
An in preposition phrase in this context is a complement: its oblique (the object of the preposition) is 'selected' by support to designate an activity which (it is implied) is performed by both the subject and the object.
A slightly different use, in which the activity itself is the object of support, does not imply participation by the subject:
The for PP in your version is not a complement—for is not 'selected' by support to express a specific semantic relationship. For will be understood here to express the reason why he supports me:
This might be appropriate if (just for instance) I were a candidate to be the organisation's next CEO: he supports me because I succeeded in changing the structure.