as machine translation is a field of machine learning research with the largest budgets and even though it's not perfect it's already pretty good, in 30 years it will likely be solved and it may not really matter which language you know
Machine translation is AI-hard. If this happens in 30 years we might as well have reached the singularity as computers will understand natural language and all of its meaning completely.
If Google Translate hasn't surpassed OP's ability to speak Chinese in 30 years then I'll eat my hat.