For the rationale behind focusing on these forty languages (out of several thousand other possibilities): Please see the post ‘Around the world in 40 ways‘. These are not the only important ones! …We just had to start somewhere.
Numbers are estimates of the total number of speakers; the proportion of native to non-native speakers varies widely between languages.
- English – 1.5 billion
- German – 180 million
- Dutch – 30 million
- Swedish – 13 million
- Norwegian – 5.3 million
- French – 312 million
- Spanish – 560 million
- Portuguese – 264 million
- Italian – 67 million
- Latin – Unknown; no native speakers
- Russian – 258 million
- Ukrainian – 41 million
- Polish – 43 million
- Czech – 12 million
- Greek – 13.5 million
- Hungarian – 14 million
- Irish – 1.8 million
- Basque – 806,000
- Turkish – 90 million
- Arabic – 380 million
- Hebrew – 9 million
- Persian – 130 million
- Hindi – 609 million
- Tamil – 87 million
- Yoruba – 47 million
- Swahili – 97 million
- Zulu – 28 million
- Vietnamese – 86 million
- Malay (including Indonesian) – 290 million
- Tagalog – 83 million
- Māori – 200,000
- Navajo (Diné) – 170,000
- Inuktitut – 100,000
- Nahuatl – 1.7 million
- Maya – 6 million
- Quechua – 7.2 million
- American Sign Language (ASL) – 860,000
[Sources: Ethnologue, 25th-27th eds., 2022-2024; national census data]