Confused with Simple Vector Spaces

Hi,

I have the vectors:

**u** = [1 2 1] **w** = [-1 0 1] **q** = [2 0 -2]** r** = [0 2 2]

and I have the vector space:

S = { a**u** + b**w** | a, b ∈ R }

I know how to answer questions which ask if a vector belongs to S - e.g. (**q **= -2**w**)

But I do not know how to answer these questions:

(b) Do **w **and **r **span the same subspace S?

(c) Do **w **and **q **span S?

(d) Do **u**, **w** and **q** span S?

I have no idea how to figure the above out being as my my material is vague and I have tried to search the internet for answers but don't understand any of it.