6
votes
1answer
432 views

What are the rules for the use of words that have a variant ending in -al? [duplicate]

Possible Duplicate: Why is it “geometric” but “theoretical”? “Electric” vs. “electrical” I think I'm clear on the difference between word ...
54
votes
5answers
3k views

Why is it “geometric” but “theoretical”?

I just came across a course name: Geometric and Theoretical Optics. The mismatched endings bug me. Why do we have both -ical and -ic endings? Is there any difference in meaning between, say, ...
15
votes
3answers
6k views

Is there a rule for which suffix to use when creating adjectives from nouns?

There are many suffixes that are used to create adjectives from nouns (-al, -ic, -ive, -y). Are there any rules used to create adjectives from nouns? In example, why is the adjective excessive, and ...