It depends on the word. It sometimes adds a syllable but not always.
-ing-ed-est-er
The stressed syllable in "disappointed" is the second syllable, pronounced as "dis-a-POINT-ed."
The stressed syllable of "interested" is the second syllable - "es" in "in-ter-est-ed".
The stress syllable in "interested" is the second syllable, "ter." So it is pronounced as "IN-ter-est-ed."
Touched only has one syllable. The -ed sounds like an extra syllable.
-ing-ed-est-er
No. -ed makes it sound like an extra syllable but it isn't.
at-tend-ed
The stressed syllable in "disappointed" is the second syllable, pronounced as "dis-a-POINT-ed."
The stressed syllable of "interested" is the second syllable - "es" in "in-ter-est-ed".
"Played" has one syllable. The ending "-ed" has no vowel (even though it is written with one), so it does not add a syllable to "play". In words ending in "t" or "d", a vowel is added before this ending, so in those cases, you do wind up with an extra syllable.
The word "short" can become "shorter" if you add a syllable to it.
The stress syllable in "interested" is the second syllable, "ter." So it is pronounced as "IN-ter-est-ed."
weed-ed, two syllables. How you do that is you say the word to claps and every syllable is a clap.
Touched only has one syllable. The -ed sounds like an extra syllable.
sus pect ed
There isn't a final syllable in the word called. The word called is only one syllable. The -ed may make it sound like another syllable but it isn't.