Well, the reason that you're having problems is not because of syntax, it's because you're trying to put a String array inside a String array. Naturally, this isn't going to work since typing in arrays must be consistent and String[] is not the same as String.
If you've got dynamic sizing, it is much cleaner and easier to work with lists. You might want to look into those instead
Lists can easily be converted to and from arrays, and provide a versatile means to dynamically add and remove elements.
Good luck!
Apa