Both back-formation and back-clipping are ways of making words by removing the endings of words. Can you explain the difference? Illustrate your point with examples.

Both back-formation and back-clipping are ways of making words by removing the endings of words. Can you explain the difference? Illustrate your point with examples.

It is true that both are means of making new words by removing the end part of the words. But they have differences. For a back-formed word, what is removed is the supposed suffix, e. g. auth← author, donate←donation, loaf←loafer, the forms -or, -ion, - coincide with the three suffixes. For back clipping, however, what is removed is usually different from the existing suffixes, e. g. ad←advertisement, gas ←gasoline , exam ← examination , etc．