These are past tense verbs/past participles. When a base word ends with a ‘short’ vowel then one consonant, we double the last consonant before adding the suffix ‘ed’. This preserves the vowel sound: a as in canned (not caned), e as in hemmed (not hemed), i as in shinned (not shined), o as in lobbed (not lobed), u as in shunned (not shuned). We don’t double consonants after unstressed vowels (opened not openned).
Base word ends with double consonant | Double last consonant of base word before adding ed |
buzzed culled dolled dulled felled fizzed fuzzed gulled hulled jazzed jelled lolled lulled mulled razzed rolled shelled tolled welled yelled | bagged banned begged bobbed bogged bugged canned chugged dabbed dimmed dobbed dubbed fanned fibbed fobbed gagged gummed gunned hammed hemmed hogged hugged hummed jabbed jammed jigged jogged lobbed logged lugged manned mobbed mugged nabbed nagged panned penned pigged pinned rammed ribbed rigged robbed rubbed sagged shammed shinned shunned sinned sobbed summed sunned tabbed tagged tanned thinned tinned tugged wagged |