Page 261 - Practical English Usage 3ed - Michael Swan, Oxford

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-ic and -ical
1
some adjectives normally ending in -ic
2
3
a
arithmetical, geometrical and pedagogical also occur.
Some of these words ended in -ical in older English (e.g. fantastical, majestical, tragical).
New adjectives which come into the language generally end in -ic, except for those ending in -logical.
some adjectives ending in -ical
biological (and many other adjectives ending in -logical)
b
In some cases, both forms exist but with a difference of meaning.
classic and classical
Classic usually refers to a famous traditional style. He's a classic 1960s hippy who has never changed. She buys classic cars and restores them.
Classical refers to the culture of ancient Greece and Rome, or to European works of art of the so-called 'classical' period in the 18th century.
She's studying classical languages and literature at Cambridge. Classical music means 'serious' music, not pop or jazz.
It's hard to learn classical guitar. comic and comical
Comic is the normal adjective for artistic comedy. comic verse comic opera
Shalcespeare's comic technique
Comical is a rather old-fashioned word meaning 'funny'. a comical expression
Many adjectives end in -ic or -ical. There is no general rule to tell you which fonn is correct in a particular case.
academic algebraic arithmetic artistic athletic catholic domestic
dramatic egoistic emphatic energetic
fantastic geometric strategic
linguistic majestic neurotic pathetic pedagogic phonetic public
semantic syntactic systematic tragic
chemical fanatical critical logical cynical mathematical grammatical mechanical
differences of meaning
medical surgical musical tactical physical topical radical
-ic and -ical 254
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