VirtueMart 2 allows you to translate many form fields by adding a language key instead of a single language value. This is possible for all fields, which are usually set up once in the store configuration. Examples for such fields are shopper field names, custom fields, etc.
To give you an idea, how it works, have a look at the following example.
In order to achieve this, go to VM Configuration > Shopper Fields > Title and enter the keys like in the following image:
Afterwards add your keys/strings to the en-GB and your language (de-DE in this example) file override files in the folder yourdomain\language\overrides. You may also use the Joomla Extensions > Language Manager > Overrides to add these lines to your language overrides.
Be aware that the language keys of the plugins even shown in the Frontend (FE) are defined in the Backend (BE). Also the countries are in the BE. Shopperfield and orderfield language keys are in the FE.