controllability and observation of a system. [Linear Systems]

So i understand that given a Matrix A, and a vector B, you can work out a controllability matrix G such that

and then the controllability depends on whether G is of full rank or not etc.

But what happens when A is an nxn matrix but B is not a 1xn vector, but instead a 2xn vector?

For example (and this is a completely made up example) -

and

how is G formed from this?

to save you having to work out:

Then the same question for observability

using the same A above, and

how is

formed?

Again, to save you having to work out