The app is probably reading your IP and presenting the store for the nation from which you are connecting.
Are you signed into your account? Accounts are for specific stores, so if you sign into your account the app should adjust the store to the one to which your account is associated. You can also scroll to the bottom of a MAS page and click the circular flag icon to change the app store from country to country.
Relax, people, Apple probably is the last company that would like to stop people from "thinking different"
But our Mexican friend is also right, Apple won't read here, this is a user forum.
So, to solve the iTunes store language problem:
Just ask a friend (or relative) to use his or her address to register an additional apple ID without a credit card.
You can then use iTunes gift cards (or purchase credits online) to charge your account and buy apps/music in the iTunes store you want.
I am German, living in the Netherlands but prefer my stuff in English, I have three Apple IDs
iPhone, iPad and my Mac have no problems with multiple IDs, you just have to enter the three of them when you back up and to update all apps simultaneously. (apparently also iCloud doesn't like multiple accounts on one machine but hey... as long as I can buy my apps I don't care)
As the money is flowing to the respective store also Apple does not mind. You just can't use a Dutch CreditCard for US purchases, that won't work.
Instructions how to set up an Apple ID without a password:
Success to all you Expats