SDL Trados Studio contains dictionaries for a number of languages. You can also create additional, custom dictionaries.
To create a custom dictionary:
Select Tools > Options from the menu bar. The Options dialog box is displayed.
Select Editor > Spelling from the navigation tree. The Spelling settings are displayed on the right.
Click Custom Dictionaries to display the Custom Dictionaries dialog box.
Create, add or modify a new custom dictionary and click Save.
When you create a dictionary, the dictionary is valid for All Languages. You can modify the dictionary so that it is valid for just one language. Click here for more information about modifying a dictionary.