- English: Cambridge CPE grade B in 2004. Proficient, with minor defects in collocation/pronunciation. Learned from formal courses and from living in the UK for a few months when he was 10.
- French: TCF grade C2 in 2011. Proficient, with a bit more defects than English. Studied and lived in France.
- Brazilian Portuguese: Native speaker
- Chinese: see github.com/cirosantilli/china-dictatorship/tree/df0852b22e585785d734ec69719eddf63f9676a5#do-you-speak-chinese
When asked, Ciro likes to say that he speaks something between 1.5 and 3.5 languages in total, depending on how you count, because Portuguese, French and English are 99.99% the same, and Chinese is completely different but Ciro only knows about 50% of it if counted optimistically.