What is the double ending of the past tense with ED

What is the double ending of the past tense with ED

There are many, as long as the last syllable of a word is a stressed closed syllable, it needs to double write the last letter and add - ed. & nbsp; the common ones are: admit & nbsp; --- & nbsp; admitted beg & nbsp; --- & nbsp; beggeddrip & nbsp; --- & nbsp; drippeddot & nbsp; --- & nbsp; docteddrop & nbsp