How can I most accurately say the simple sentence:
I have been studying Chinese for 4 years.
This is a very simple phrase, and I am surprised at myself for not being confident in which one of the following is accurate:
我已经学习中文四年了。
我学习中文已经四年了。
我已经学了四年的中文。
With regard to the first two, I am particularly confused about the placing of "已经," and whether it should be before or after the verb. As for the third, it is a different sentence structure, is it incorrect?