Which functional group would be given priority while naming an organic compound with more than one functional group

I want to know that in nomanclature including functional groups,if there are more than 2 functional groups then which would be given priority.

alphabetical and this does not count the di or tri eg if you had substituted pentane with C2H5 attached to C=3 and two CH3 group attached to C2, this would be called 3-ethyl-2,2-dimethylpentane (ethyl before methyl) [the di- prefix is not considered in the alphabetical order]

Read http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/nomen1.htm

And if ketone and aldehyde are present then?