better to do

[keitra]

Can I say 'Who is better to do that than you.' instead of 'Who better to do that than you.'?

[geofbob]

Yes, though the second way sounds more elegant. This is assuming you're meaning to say/write that the second person IS the best person to do the thing. If, however, you were asking a genuine question, then "who can do this better than you?" might be clearer.

[sft42]

The first is a most likely to be a direct question only asked of a person who has voiced an opinion that they are unsuitable for a given task, while the second comment could be a question or a form of flattery or question....Clearer versions would be geofbob's version for the question and "You are the best person for the job" for the flattery.

[geofbob]

I've been looking at this again, keitra, and I think a slight alteration to the order of the words would also improve your examples -"who is better than you to do that?" & "who better than you to do that"?. (But I also agree with sft - if flattery is intended, then a straightforward statement might be clearer and easier.)