Language Proficiency?

[Blue Star Mom]

How proficient do you become in your language? My son has been given Mandarin Chinese to learn and the task of learning all the characters/alphabet plus the tones for the different combinations seems like a pretty daunting task. Fortunately he has a good ear for music so he'll hear the tones. How long will he be given to learn Mandarin? His MOS is communications. He definitely has his work cut out for him!