Try also

    wget https://iso639-3.sil.org/sites/iso639-3/files/downloads/iso-639-3.tab
    grep -xFf <(grep -o ^... iso-639-3.tab) /usr/share/dict/british-english 

You can make whole English sentences out of ISO 639-3 language codes:

    woo yes, any fun car has the big dry cat, and thy ads are zen too; bye!

using the codes of Manombai Nyankpa Anyin Fulniô Galibi_Carib Haisla Chitwania_Tharu Biangai Darai Catalan Ansus Tha Adamorobe_Sign_Language Western_Arrarnta Zenaga Xicotepec_De_Juárez_Totonac Pouye