| Anatolian | | | Hieroglypic Hittite*, Hittite (Kanesian)*, Luwian*, Lycian*, Lydian*, Palaic* |
| Baltic | | | Latvian (Lettish), Lithuanian, Old Prussian* |
| Celtic | Brythonic | | Breton, Cornish, Welsh |
| Continental | | Gaulish* |
| Goidelic or Gaelic | | Irish (Irish Gaelic), Manx*, Scottish Gaelic |
| Germanic | East Germanic | | Burgundian*, Gothic*, Vandalic* |
| North Germanic | | Old Norse* (see Norse), Danish, Faeroese, Icelandic, Norwegian, Swedish |
| West Germanic (see Grimm's law) | High German | German, Yiddish |
| Low German | Afrikaans, Dutch, English, Flemish, Frisian, Plattdeutsch (see German language) |
| Greek | | | Aeolic*, Arcadian*, Attic*, Byzantine Greek*, Cyprian*, Doric*, Ionic*, Koinē*, Modern Greek |
| Indo-Iranian | Dardic or Pisacha | | Kafiri, Kashmiri, Khowar, Kohistani, Romany (Gypsy), Shina |
| Indic or Indo-Aryan | | Pali*, Prakrit*, Sanskrit*, Vedic* |
| Central Indic | Hindi, Hindustani, Urdu |
| East Indic | Assamese, Bengali (Bangla), Bihari, Oriya |
| Northwest Indic | Punjabi, Sindhi |
| Pahari | Central Pahari, Eastern Pahari (Nepali), Western Pahari |
| South Indic | Marathi (including major dialect Konkani), Sinhalese (Singhalese) |
| West Indic | Bhili, Gujarati, Rajasthani (many dialects) |
| Iranian | | Avestan*, Old Persian* |
| East Iranian | Baluchi, Khwarazmian*, Ossetic, Pamir dialects, Pashto (Afghan), Saka (Khotanese)*, Sogdian*, Yaghnobi |
| West Iranian | Kurdish, Pahlavi (Middle Persian)*, Parthian*, Persian (Farsi), Tajiki |
| Italic | (Non-Romance) | | Faliscan*, Latin, Oscan*, Umbrian* |
| Romance or Romanic | Eastern Romance | Italian, Rhaeto-Romanic, Romanian, Sardinian |
| Western Romance | Catalan, French, Ladino, Portuguese, Provençal, Spanish |
| Slavic or Slavonic | East Slavic | | Belarusian (White Russian), Russian, Ukrainian |
| South Slavic | | Bulgarian, Church Slavonic*, Macedonian, Serbo-Croatian, Slovenian |
| West Slavic | | Czech, Kashubian, Lusatian (Sorbian or Wendish), Polabian*, Polish, Slovak |
| Thraco-Illyrian | | | Albanian, Illyrian*, Thracian* |
| Thraco-Phrygian | | | Armenian, Grabar (Classical Armenian)*, Phrygian* |
| Tokharian (W China) | | | Tokharian A (Agnean)*, Tokharian B (Kuchean)* |