1. What do the following words have in common?

ERR
HEM
HER
PAGE
PANT
ELOPE

2. What do the following words have in common?

ONE
AWL
OWN
EDGE
OUGHT

HINTS:
1. The same three letters will change each word into a new one.
2. The same two letters will change each word into a new one.

Answers:

1. Each word can be either preceded or followed by the letters ANT to form new words:

ERRANT
ANTHEM
ANTHER
PAGEANT
PANTHER
ANTELOPE

2. Each word can be preceded by DR to form new words:

DRONE
DRAWL
DROWN
DREDGE
DROUGHT