I have always wondered about the similarity of the two words
Astronomy and Astrology
that describe two very different things but have their beginning in common and are sometimes confused in everyday language. The linguistic difference (if one can say so) between them is only in the endings '-onomy' and '-ology'. Two further examples are
Topology and Topography
Geology and Geography
where now we have the endings '-ology' and '-ography'.
What are the meanings of the different endings '-onomy', '-ology' and '-ography' ?
I would also be curious about whether it is a coincidence that '-ology' appears in all the examples above? Does it maybe have historical reasons?
And furthermore, are there more such pairs to be found? (I can't think of any others)