Present participle & Past participle (with last letter doubled)

Present participle (with last letter doubled)

Hop → Hopping
Stop → Stopping
Run → Running
Sit → Sitting
Plan → Planning
Swim → Swimming
Get → Getting
Pin → Pinning
Rub → Rubbing
Tap → Tapping
Skip → Skipping
Wrap → Wrapping
Shop → Shopping
Drop → Dropping
Clap → Clapping
Begin → Beginning
Admit → Admitting
Prefer → Preferring
Permit → Permitting
Commit → Committing

Past participle (with last letter doubled)

Hop → Hopped
Stop → Stopped
Plan → Planned
Pin → Pinned
Rub → Rubbed
Tap → Tapped
Skip → Skipped
Wrap → Wrapped
Shop → Shopped
Drop → Dropped
Clap → Clapped
Refer → Referred
Admit → Admitted
Permit → Permitted
Commit → Committed
Prefer → Preferred
Occur → Occurred
Transmit → Transmitted