1. What do the following words and partial words have in common?

SUL
PAN
PAS
SEN
POE
WIN

2. What do the following words have in common?

NOW
SIP
WOE
MONEY
PLAN

Answers:

1. Each clue word can be followed by TRY to make a new word:

SULTRY
PANTRY
PASTRY
SENTRY
POETRY
WINTRY

2. Each word can be changed into a new one by inserting a K somewhere in the word:

KNOW
SKIP
WOKE
MONKEY
PLANK