>>I understand that the particle /tu/ in Sanskrit serves a similar semantic
function and I'm guessing it is the historical precedent of /to/.

 

Your guess is right for raamastu = raam to  kind of structures. 

 

>>However,
my consultants are not using /tu/ they are using /to/!

>>Reiterating my query more precisely, can I consider this to be a case of
code-mixing?

 

Obviously, it is code-mixing only. Because there is no 'to' in Sanskrit and 'tu' is the correct form to be used in all the examples cited.


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