Dropped syllables, syncope

Does the word interesting have three syllables or four? How many syllables in the word favorite, every, and different?
Transcript

Dictionaries show it both as a three and four syllables, as in in-tres-ting and in-ter-es-ting. The discussion about that word led to things other than the number of syllables in the word, but it is only the optional number of syllables in the word interesting, as well as other common words, that I'm going to talk about today.

The linguistic term for the loss of a syllable in spoken word is syncope, but I simply refer to it as dropped syllables.

Other examples of dropped syllables are the words every, favorite, and different.

That was:

ev-er-y versus ev-ry
or
fav-o-rite versus fav-rite
or
dif-fer-ent versus diff-rent

Dropping syllables occurs mostly on high-frequency words, and dictionaries are pretty good about showing both options when two choices of pronunciation are available.

The syllable that can be dropped, not surprisingly, follows a pattern. The syllables before or after a stressed syllable in a word are often unstressed. (This is opposed to a secondary stress that can occur two syllables apart from a stressed syllable.) Only the vowel sounds of unstressed syllables can get dropped, and usually the original word needed to have at least three syllables to begin with. I mentioned four words above, which I'll repeat now.

interesting
every
favorite
different

Here are some more examples. (I'm only going to pronounce these the less formal way, with the dropped syllable):

laboratory
family
vegetable
camera
mystery
beverage
restaurant

I also want to tell you the most common 2-syllable word can be reduced to a single syllable: s'pose (for suppose), as in "I s'pose I can help you tomorrow."

Also, like most informal options of pronouncing English, they may go away is the word is emphasized in a sentence. For instance, the word every. In normal speech, it drops to 2 syllables, every. However, if I were emphasizing that word, it may go back to the more proper 3 syllables, every. For example, in the sentence:

You don't need to practice every day, but you should try to most days.

I stressed the word every, and it was said with three syllables, as ev-e-ry.

Now, I do need to say, North Americans and British do this differently. So if you are more exposed to British English, you will not notice this to the same extent.

One last thing I found interesting when double checking facts for this episode, when I went to Merriam Webster Online to listen to their audio, they almost always pronounce the word with the less formal pronunciation. However, they sometimes show the syllabic breakdown with the extra syllable, and the phonetic transcription with the dropped syllable. It's an interesting discrepancy.