For some reason, many people cannot pronounce the word mischievous.  I’ve also found that it is one of the most adamantly defended mistakes in common English.  If you don’t already know, here’s the problem:

A mischievous person is a person who is fond of causing trouble or mischief.  The word is easy to pronounce.  It’s three syllables: miss, chiv, and us with the stress of the first syllable.  But people want to say it like there’s another letter stuck in there.  If it were spelled mischievious then you could pronounce it in four syllables: miss, chee, vee, us, with the second stressed.  Unfortunately for these people, these wrongees, that’s not how it’s spelled.

And don’t think that this is a case of regional differences.  Some words, like aluminum, have alternate spellings in different parts of the English speaking world (British: aluminium).  These words at least could prompt discussion.  Miss-chee-vee-us is wrong everywhere.

Sometimes people try to correct the error by pronouncing the word in three syllables, miss, chee, and vus, with the stress on the second, which is less wrong but still pretty wrong.  I suspect the sticking point is that second syllable spelled chiev.  People for whom reading is more prominent than speaking sometimes struggle with derivative words because they lose their phonetic spellings.  Mischievous comes from mischief. Both the pronunciation and the spelling are derived from the root word, hence mischief-us.

Perhaps you would get it right if you practiced the proper pronunciation.  Say mischief-us ten times.  Remember: no matter how loudly you insist, you’re still wrong.  Google it.