Can't access to cortana

[Prathameshk]

Hello Guyzz..,i have lumia 625 with os wp8.1,i have some problems with cortana,i formatted my 625 yesterday,again i unlocked my phone and unrolled to
devloper preview,after i changed region ,language and speech to USA but i am not able to access cortana....what should i do?plz help me.....

 

[David P2]

Reigon, keyboard language (you have to install and activate the US keyboard) and speech (same applies). Region format (for dates and currency) can be anything you like.