Simple Antonyms 

Pass/fail

Nancy passed her road test.

Nancy failed her road test.

Simple antonyms are contradictory. Nancy has to either pass or fail her road test. This means that only one sentence can be true.

Gradable Antonyms

Clean/messy

Sara’s room was clean.

Sara’s room was messy.

These are gradable antonyms because her room can’t be both clean and messy.  It has to be one or the other.

Reverses

open/close 

The store was open today.

The store was closed today.

These are reverses because they denote motion or change in opposite directions.

Converses

father/son

Jerry is Tom’s father.

Tom is Jerry’s son.

Father and son are a converse pair because there is an asymmetric relationship between the two.

 

Taxonomic Sisters 

lizards/chameleons 

Lizards are a kind of reptile.

Chameleons are a kind of reptile.

Lizards and chameleons are taxonomic sisters because they are reptiles. They are the hyponym of the hyperonym reptile.