Question

A present participle and past participle in which the last letter is doubled. ​

Answer 1

There is a supposed 'rule' in American English that if the final syllable in a multi-syllable verb is unaccented/ unstressed/ un-emphasised, then the last letter of that syllable is _not_ doubled in forming the present participle - eg “worshiping”, “kidnaping

Answer 2

Answer:

planned, travelled are examples of past participle last letter is doubled.

rotting ,stopping are examples of present participle where last letter is doubled.