Side Ops #1. Extract Russian Interpreter.
Side Ops #2. Extract Pashto Interpreter .
Side Ops #3. Extract Afrikaans Interpreter.
Side Ops #4. Extract Kikongo Interpreter.
These missions are rather simple especially if you start them after having Stealth camo p.p. at least and completing the main 30 missions. They are even easier after completing all 50 missions.
For these 4 you will gain intel on translating the following languages. This is important for completing certain mission objectives during the game. You will be able to see the dialog as sub-titles in English now for every language you have extracted a person for.