Collins Cobuild English Grammar (199 page)

R67
     All the verbs described in
R66
, except
handicap
, can have their
-ing
participle and past form spelled with a single consonant letter in American English.

travel		traveling		traveled
worship		worshiping		worshiped

R68
    Here is a list of the verbs whose final consonant letter is doubled before
ing
and
ed
in both British and American English:

ban

bar

bat

beg

blot

blur

bob

brag

brim

bug

cap

chat

chip

chop

clap

clog

clot

cram

crib

crop

cup

dab

dam

dim

din

dip

dot

drag

drop

drug

drum

dub

fan

fit

flag

flap

flip

flop

fog

fret

gas

gel

glut

grab

grin

grip

grit

grub

gun

gut

hem

hop

hug

hum

jam

jet

jig

jog

jot

knit

knot

lag

lap

log

lop

man

mar

mob

mop

mug

nag

net

nip

nod

pad

pat

peg

pen

pet

pin

pit

plan

plod

plug

pop

prod

prop

rib

rig

rip

rob

rot

rub

sag

scan

scar

scrap

scrub

ship

shop

shred

shrug

shun

sin

sip

skid

skim

skin

skip

slam

slap

slim

slip

slop

slot

slum

slur

snag

snap

snip

snub

sob

spot

squat

stab

star

stem

step

stir

stop

strap

strip

strut

stun

sun

swab

swap

swat

swig

swot

tag

tan

tap

thin

throb

tip

top

trap

trek

trim

trip

trot

vet

wag

wrap

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