| Proto-Austronesian | map-000 | *dua |
| Proto-Cen Malayo-Polynesian | plf-002 | *dua |
| Proto-Cen E Malayo-Polynesian | pqe-002 | *dua |
| Proto-Gbaya | gba-001 | *dùà |
| Jawe | jaz-000 | -dua |
| Dàn | dnj-001 | =dua |
| nynorsk | nno-000 | Dua |
| Plautdietsche Sproak | pdt-000 | Dua |
| Puyuma | pyu-000 | Dua |
| Türkçe | tur-000 | Dua |
| Chru | cje-000 | Dua: |
| Naadh | nus-000 | Duä |
| tiếng Việt | vie-000 | Dừa |
| Meʼen | mym-000 | d=ua |
| Kĩkamba | kam-000 | dUa |
| Malayu Ambong | abs-000 | dua |
| Bahsa Acèh | ace-000 | dua |
| Akan | aka-000 | dua |
| Araki | akr-000 | dua |
| Wakasihu | alo-000 | dua |
| toskërishte | als-000 | dua |
| ISO 639-3 | art-001 | dua |
| ISO 639-2/T | art-002 | dua |
| ISO 639-2/B | art-003 | dua |
| ISO 639 | art-005 | dua |
| Romániço | art-013 | dua |
| Communicationssprache | art-050 | dua |
| Pasilingua | art-055 | dua |
| Kosmos | art-057 | dua |
| Lingvo Kommona | art-085 | dua |
| Axiom-Variant | art-100 | dua |
| Frendo | art-104 | dua |
| Unitario | art-108 | dua |
| filename extensions | art-335 | dua |
| Bucardo | art-352 | dua |
| IETF language tags | art-420 | dua |
| Buruwai | asi-000 | dua |
| Pamplona Atta | att-000 | dua |
| Avestan | ave-000 | dua |
| azərbaycanca | azj-000 | dua |
| basa Bali | ban-000 | dua |
| Hata Batak | bbc-000 | dua |
| Bonggi | bdg-000 | dua |
| Poso | bdl-001 | dua |
| Boepinang Bajau | bdl-005 | dua |
| Kaleroang Bajau | bdl-006 | dua |
| Kayuadi Bajau | bdl-007 | dua |
| Kolo Bawah Bajau | bdl-008 | dua |
| Lakaramba Bajau | bdl-009 | dua |
| Lakonea Bajau | bdl-010 | dua |
| Langara Laut Bajau | bdl-011 | dua |
| Lapulu Bajau | bdl-012 | dua |
| Lauru Bajau | bdl-013 | dua |
| Lemo Bajau | bdl-014 | dua |
| Luwuk Bajau | bdl-015 | dua |
| Padei Laut Bajau | bdl-017 | dua |
| Budong Budong | bdx-000 | dua |
| Betawi | bew-000 | dua |
| Bima | bhp-000 | dua |
| Popalia | bhq-000 | dua |
| Banjar | bjn-000 | dua |
| Bonerate | bna-000 | dua |
| Masiwang | bnf-000 | dua |
| Bantik | bnq-000 | dua |
| Biyom | bpm-000 | dua |
| Ai Banda | bpq-000 | dua |
| Sekola Lonthoir Banda | bpq-001 | dua |
| Sekola Neira Banda | bpq-002 | dua |
| Mandailing | btm-000 | dua |
| Simalungan | bts-000 | dua |
| Karo | btx-000 | dua |
| Bobot | bty-000 | dua |
| basa ugi | bug-001 | dua |
| Soppeng Buginese | bug-002 | dua |
| Komiya | bva-000 | dua |
| Batak | bya-000 | dua |
| Buton | cia-001 | dua |
| Western Cham | cja-000 | dua |
| Chru | cje-000 | dua |
| Phan Rang Cham | cjm-000 | dua |
| Chuave-Swick | cjv-000 | dua |
| Weicheng | cng-009 | dua |
| Qırımtatar tili | crh-000 | dua |
| Nyala | daj-000 | dua |
| Kitaita | dav-000 | dua |
| Idaʻan | dbj-000 | dua |
| Agta | dgc-000 | dua |
| Yacouba | dnj-002 | dua |
| Dan | dnj-003 | dua |
| Dom | doa-000 | dua |
| Dom-Boumai | doa-001 | dua |
| Duanoʼ | dup-000 | dua |
| Embaloh | emb-000 | dua |
| Esperanto | epo-000 | dua |
| Fanti | fat-000 | dua |
| vosa Vakaviti | fij-000 | dua |
| suomi | fin-000 | dua |
| gagauz dili | gag-000 | dua |
| Gbin | ggu-000 | dua |
| Gaeilge | gle-000 | dua |
| Gana | gnq-000 | dua |
| Gumuz Sai | guk-000 | dua |
| Gojjam | guk-002 | dua |
| Ngäbere | gym-000 | dua |
| עברית | heb-000 | dua |
| ISO 259-3 | heb-001 | dua |
| Helong | heg-000 | dua |
| Proto-Hmong | hmn-001 | dua |
| Proto-Western-Hmong | hmx-001 | dua |
| Hmoob | hnj-000 | dua |
| Iban | iba-000 | dua |
| Ido | ido-000 | dua |
| Iloko | ilo-000 | dua |
| Iranun | ilp-000 | dua |
| bahasa Indonesia | ind-000 | dua |
| Alor Malay | ind-001 | dua |
| Orang Hulu | jak-000 | dua |
| Loglan | jbo-001 | dua |
| Kubo | jko-000 | dua |
| Jowulu | jow-000 | dua |
| Jarai | jra-000 | dua |
| Northern Tukang Besi | khc-000 | dua |
| Kurmancî | kmr-000 | dua |
| Komo | kmw-000 | dua |
| Selako | knx-000 | dua |
| Kodi | kod-000 | dua |
| Kapingamarangi | kpg-000 | dua |
| Mountain Koiari | kpx-000 | dua |
| Garo | kqr-001 | dua |
| Chimbu | kue-000 | dua |
| Munga | ldk-000 | dua |
| Liabuka | lix-000 | dua |
| Nguna | llp-000 | dua |
| bregagliotto | lmo-001 | dua |
| Proto-Austronesian | map-000 | dua |
| Ternate Pasar | max-000 | dua |
| Moro Magindanau | mdh-001 | dua |
| Mandar | mdr-000 | dua |
| Melanau | mel-000 | dua |
| Lom | mfb-000 | dua |
| Kupang Malay | mkn-000 | dua |
| Muna | mnb-000 | dua |
| Mongondow | mog-000 | dua |
| Mualang | mtd-000 | dua |
| Mentawai | mwv-000 | dua |
| Hmoob Dawb | mww-000 | dua |
| napulitano | nap-000 | dua |
| Nasioi | nas-000 | dua |
| Tura | neb-000 | dua |
| Ndao | nfa-000 | dua |
| Nias | nia-000 | dua |
| Northern Nias | nia-001 | dua |
| Southern Nias | nia-002 | dua |
| Nukuoro | nkr-000 | dua |
| Namakir | nmk-000 | dua |
| nynorsk | nno-000 | dua |
| Napu | npy-000 | dua |
| Norn | nrn-000 | dua |
| Orma | orc-000 | dua |
| Pangasinan | pag-000 | dua |
| Proto-Minahasan | phi-002 | dua |
| Proto-Sangiric | phi-004 | dua |
| Proto-Palawan | phi-005 | dua |
| Quezon Palawan | plc-001 | dua |
| Taut Batu | plc-002 | dua |
| Proto-Cen Malayo-Polynesian | plf-002 | dua |
| Southwest Palawano | plv-000 | dua |
| Canipaan Palawan | plv-002 | dua |
| Brooke’s Point Palawano | plw-000 | dua |
| Palawano Batak | plw-001 | dua |
| Punan-Nibong | pne-000 | dua |
| Proto-South Sulawesi | poz-004 | dua |
| Pipikoro | ppk-000 | dua |
| Proto-Cen E Malayo-Polynesian | pqe-002 | dua |
| Pitu Ulunna Salo | ptu-000 | dua |
| Molbog | pwm-000 | dua |
| Nanwang Puyuma | pyu-006 | dua |
| Pilam Puyuma | pyu-007 | dua |
| Rhade | rad-000 | dua |
| Southern Raglai | rgs-000 | dua |
| Ruáingga | rhg-000 | dua |
| Nyaturu | rim-000 | dua |
| Chahi | rim-001 | dua |
| Tae' | rob-000 | dua |
| Kihorombo | rof-000 | dua |
| Mkuu | rof-001 | dua |
| Northern Raglai | rog-000 | dua |
| Sileibi | sbq-000 | dua |
| Toraja Saʼdan | sda-000 | dua |
| Mapun | sjm-000 | dua |
| Sichule | skh-000 | dua |
| Pangutaran | slm-000 | dua |
| Samal | sml-000 | dua |
| Simeulue | smr-000 | dua |
| Basa Samawaʼ | smw-000 | dua |
| Sangil | snl-000 | dua |
| Saparua | spr-000 | dua |
| shqip | sqi-000 | dua |
| Siroi | ssd-000 | dua |
| Batuan | sse-001 | dua |
| Sinasina | sst-000 | dua |
| basa Sunda | sun-000 | dua |
| svenska | swe-000 | dua |
| Kiswahili | swh-000 | dua |
| Sangir | sxn-000 | dua |
| Inanwatan | szp-000 | dua |
| Tagbanwa | tbw-000 | dua |
| Tamari | tbz-000 | dua |
| Tondano | tdn-000 | dua |
| Tebilung | tgb-000 | dua |
| Tagbanwa | tgt-000 | dua |
| Timbe | tim-000 | dua |
| Adasen | tiu-000 | dua |
| Talaud | tld-000 | dua |
| Waibuk | tmd-000 | dua |
| Temuan | tmw-000 | dua |
| Maiani | tnh-000 | dua |
| Tonsawang | tnw-000 | dua |
| Tok Pisin | tpi-000 | dua |
| Sivisa Titan | ttv-000 | dua |
| Türkçe | tur-000 | dua |
| Sedoa | tvw-000 | dua |
| Ashanti | twi-001 | dua |
| Termanu | twu-000 | dua |
| Tonsea | txs-000 | dua |
| Uyghurche | uig-001 | dua |
| Ukuriguma | ukg-000 | dua |
| Urdu | urd-002 | dua |
| Kulon-Pazeh | uun-000 | dua |
| Wejewa | wew-000 | dua |
| Muduapa | wiv-000 | dua |
| Wano | wno-000 | dua |
| Bungu | wun-000 | dua |
| Wungu | wun-001 | dua |
| Kambera | xbr-000 | dua |
| Lewa Kambera | xbr-001 | dua |
| Southern Kambera | xbr-002 | dua |
| Umbu Ratu Nggai Kambera | xbr-003 | dua |
| Tamuan | xdy-001 | dua |
| Kenyah | xkl-000 | dua |
| Bahasa Manado | xmm-000 | dua |
| Ketengban | xte-001 | dua |
| Yaben | ybm-000 | dua |
| Melayu | zlm-000 | dua |
| Bahasa Malaysia | zsm-000 | dua |
| Dàn | dnj-001 | dua" |
| Bahasa Melayu Pontianak | zlm-013 | dua' |
| Hindi | hin-002 | dua* |
| Bandjalang | bdy-000 | dua- |
| Nake | nbk-000 | dua- |
| Pamplona Atta | att-000 | dua: |
| Ft. Hall | shh-001 | duaʼ |
| Siocon Subanon | suc-000 | dua’ |
| Kayan R. Kayan | xkn-000 | dua’ |
| Roti | bdl-002 | duà |
| Tagabawa | bgs-000 | duá |
| Golin | gvf-000 | duá |
| Iloko | ilo-000 | duá |
| Ruáingga | rhg-000 | duá |
| Zeneize | lij-002 | duâ |
| Gangam | gng-000 | duã |
| la lojban. | jbo-000 | duʼa |
| Tuyuca | tue-000 | duʼa |
| Uyghurche | uig-001 | duʼa |
| Phan Rang Cham | cjm-000 | du̯ā |
| Hànyǔ | cmn-003 | dù ā |
| tiếng Việt | vie-000 | dùa |
| Bofi | bff-000 | dùà |
| Gbeya | gba-000 | dùà |
| Yaáyuwee | gya-000 | dùà |
| Manza | mzv-000 | dùà |
| Ngbaka | nga-000 | dùà |
| íslenska | isl-000 | dúa |
| Ruáingga | rhg-000 | dúa |
| Samalan | sse-002 | dúa |
| Tausug | tsg-000 | dúa |
| kɔ́ɔnzime | ozm-000 | dúʼá |
| français | fra-000 | dû à |
| lengua lígure | lij-000 | dûá |
| lengua lígure | lij-000 | dûâ |
| Yele | yle-001 | düa |
| Tuyuca | tue-000 | dũʼã |
| tiếng Việt | vie-000 | dưa |
| duleri dom | tde-000 | dᵘa |
| idyoli donge | dmb-000 | dᵘaː |
| tiếng Việt | vie-000 | dứa |
| tiếng Việt | vie-000 | dừa |
| tiếng Việt | vie-000 | dựa |
| Anakalangu | akg-000 | d’ua |
| Tuyuca | tue-000 | ʼdua |
| Bakwé | bjw-000 | ˈDua |
| Djingili | jig-000 | ḍu-a- |
| Odual | odu-000 | ḍụa |
| Bima | bhp-000 | ḏua |
| ISO 639-PanLex | art-274 | dua-000 |
| Wenma | zhd-000 | duã.1 thǝn.2 |
| Tanxi | tjs-002 | duã₃₃ |
| Chuanqiandian | cqd-000 | dua₆ |
| Dayak Bakatiq-Sara/Riok | bei-000 | dua7 |
| Nasioi | nas-000 | dua7 |
| Kayan | ree-000 | dua7 |
| Siocon Subanon | suc-000 | dua7 |
| Sindangan Subanun | syb-000 | dua7 |
| Tarunggareh | trt-000 | dua 7a |
| Dondo | dok-000 | dua7mo |
| Lauje Ampibabo | law-001 | dua7mo |
| català | cat-000 | Duaa |
| Esperanto | epo-000 | Duaa |
| español | spa-000 | Duaa |
| Urdu | urd-002 | duaa |
| Pular | fuf-000 | duʼaa |
| eesti | ekk-000 | düaad |
| eesti | ekk-000 | düaad- |
| Jelgoore | fuh-001 | duʼaade |
| Yaagaare | fuh-002 | duʼaade |
| Gurmaare | fuh-003 | duʼaade |
| Moosiire | fuh-004 | duʼaade |
| Ibibio | ibb-000 | duaak |
| eesti | ekk-000 | duaal |
| Nederlands | nld-000 | duaal |
| suomi | fin-000 | duaali |
| suomi | fin-000 | duaaliavaruus |
| suomi | fin-000 | duaalin duaali |
