1. What do the following words have in common?

STILL
HALF
SHELF
CHARMED

2. What do the following words have in common?

WIT
BATH
NOTE
TRUTH

3. What do the following words have in common?

SHIN
TALL
COVE

Answers:

1. Each word can be followed by LIFE:

STILL LIFE
HALF-LIFE
SHELF LIFE
CHARMED LIFE

2. Each word can be preceded by HALF:

HALF-WIT
HALF BATH
HALF-NOTE
HALF-TRUTH

3. Each word can be changed into a new one by adding Y:

SHIN - SHINY
TALL - TALLY
COVE - COVEY