| Part of speech | cardinal number |
|---|---|
| Pronunciation | /ˈθɜːtɪ/ |
| Hyphenation | thir·ty |
| Shavian alphabet | 𐑔𐑻𐑑𐑦 |
| Afrikaans | dertig |
|---|---|
| Albanian | tridhjetë |
| Catalan | trenta |
| Czech | třicet |
| Danish | tredive |
| Dutch | dertig |
| English (Old English) | þritig; þrittig |
| Esperanto | tridek |
| Finnish | kolmekymmentä |
| French | trente |
| German | dreißig |
| Greek | τριάντα |
| Hungarian | harminc |
| Icelandic | þrjátíu |
| Italian | trenta |
| Jamaican Patois | toti |
| Latin | triginta |
| Low German | dörtig |
| Luxemburgish | drësseg |
| Norwegian | tredve |
| Papiamento | trinta |
| Portuguese | trinta |
| Saterland Frisian | trüütich |
| Spanish | treinta |
| Sranan | dritenti |
| Swahili | thelathini |
| Swedish | trettio |
| Thai | สามสิบ |
| West Frisian | tritich |
| Yiddish | דרײַסיק |