Besides can be either a preposition or a adverbe.
The following is from the on-line WM Dictionary:
http://www.merriam-webster.com/dictionary/besides?show=0&t=1357792369
be·sides preposition \bi-ˈsīdz, bē-\
Definition of BESIDES
1
: other than, except <no one besides us>
2
: together with <a decision that, besides being practical, is morally right>
Examples of BESIDES
- She wants to learn other languages besides English and French.
- Besides its famous cakes, the bakery also makes delicious breads and cookies.
- These salads are delicious besides being healthy.
- I'm not ready to get married yet. Besides which, I enjoy living alone.
2besides
adverbDefinition of BESIDES
1
: as well : also
2
Examples of BESIDES
- They serve pasta and many other foods besides.
- I'm not ready to get married yet. Besides, I enjoy living alone.
