1. What do the following rhyming words have in common?

COT
TOT
ROT
SOT

2. What do the following words have in common?

INK
ICE
ANT
OUCH
EIGHT

HINT:
2. The same two letters, placed in the same position, will yield new words.

Answers:

1. They have rhyming homophones:

CAUGHT / TAUGHT / WROUGHT / SOUGHT

2.  Each word can be preceded by SL:

SLINK / SLICE / SLANT / SLOUCH / SLEIGHT