There are two types of mandarin used nowadays.
The first one is Traditional Chinese, this is the early Mandarin language.
The characters in language has more strokes and more complicated to ctudy.
The second one is Simplified Chinese. The characters has less strokes and easier to memorize.
China (as the largest population using Mandarin) uses the second one as their national language. It is a part of their way to make their language easier to study for foreign countries, which will help the economic growth in China as well.
However the first one, Traditional Chinese is still being used in some countries like Taiwan.
I personally prefer learning Simplified Chinese because it's easier ;p
Which one will you choose?
