indentured and chattel .|.
The two main kinds of slavery historically were chattel slavery, where enslaved individuals were considered the property of their owners and had no rights, and debt bondage, where individuals were enslaved to work off a debt but still had some limited rights.
The two main kinds are discrete and continuous.
there are far more than two main kinds of submarines. The only two sections I can think of to separate them are fast attack and Boomers or Ballistic Missle.
consumers and producers.
kinetic and potential
to save the union and abolish slavery
quiet and explosive
The two main types of swamp are "true" or swamp forests and "transitional" or shrub swamps.
Sail boats and power boats are the two main types of pleasure craft.
The action verb and the linking verb.
Slavery disputes and trading rights.
Eucalyptus and Australian acacia