Itnaa, Itni and Itney / itnay / itne (whichever way U pronounce is acceptable) = this much.
Muze ek cup itnaa paani chaahiye
itni see baat ke liye gussaa kyu hote ho ?
Unhey itney he aam chaahiye.
Jitnaa / jitni / jjitney - U can use for - that much, upto, as much as, overwhelming etc. etc.
Ex : Jitnaa pyaar aap Mata Pitaa ko day sakate hai, utnaa / ottnaa kam hai.
Jitni bhi mai aapki taarif karu ootni kam hai.
Jitnaa / jitney chaaho utnaa / ootnaa chillla o.
Jitnaa, U can also use as Verb : = to Win
Would U like to try making yr own sentences ?
Pl do so.
I look forward to hearing from you.