Here is the full list of all 40 Linguist FPS - there are The Language Learning FPS achievements.
Complete the training level. English US
Complete the training level. Chinese
Complete the training level. Chinese Pinyin
Complete the training level. English AUS
Complete the training level. English UK
Complete the training level. French
Complete the training level. German
Complete the training level. Italian
Complete the training level. Japanese Kana
Complete the training level. Japanese Kanji
Complete the training level. Japanese Romaji
Complete the training level. Korean
Complete the training level. Polish
Complete the training level. Portuguese
Complete the training level. Russian
Complete the training level. Spanish europe
Complete the training level. Spanish Latam
Complete the training level. Swedish
Complete the training level. Ukrainian
Complete in Normal Difficulty Mode. English US
Complete in Normal Difficulty Mode. Chinese
Complete in Normal Difficulty Mode. Chinese Pinyin
Complete in Normal Difficulty Mode. English AUS
Complete in Normal Difficulty Mode. English UK
Complete in Normal Difficulty Mode. French
Complete in Normal Difficulty Mode. German
Complete in Normal Difficulty Mode. Italian
Complete in Normal Difficulty Mode. Japanese Kana
Complete in Normal Difficulty Mode. Japanese Kanji
Complete in Normal Difficulty Mode. Japanese Romaji
Complete in Normal Difficulty Mode. Korean
Complete in Normal Difficulty Mode. Polish
Complete in Normal Difficulty Mode. Portuguese
Complete in Normal Difficulty Mode. Russian
Complete in Normal Difficulty Mode. Spanish europe
Complete in Normal Difficulty Mode. Spanish Latam
Complete in Normal Difficulty Mode. Swedish
Complete in Normal Difficulty Mode. Ukrainian
Complete Recruit - Survival Mode - The City
Complete Commando - Survival Mode - The City