Taller is <inalta>. Please do not argue. Wrong translation of taller with <<mare>>
Agreed. I also thought you had to use "decât" when comparing differences as opposed to "ca."
I do not yet have a sense to comment on <<decat>> and <<ca>> Both of them sound to me the same correct constructions.
My girlfriend (native Romanian) says decat and ca are pretty much synonymous for comparisons.