Indoor cats and outdoor cats are the compound subject (not including the and), and require is the verb.
A subject can be compound or singular. If it is compound, then both are the subject. Example:John and Jeff rode their bikes.
compound subject
A compound subject is a sentance with two or more subjects.
Tony and I went to the movies. Tony and I is the compound subject.
a compound subject is two or more subjects joined by a conjuction
The subject isn't compound -- Kate is the subject.Wrote and edited is the compound predicate.
Some compound subject pronouns are someone, anyone, everyone, and whoever.
first of all your sentence is incorect! it would be "What is "a" compound subject"anyways a compound subject is when you have two subjects like in this sentence-Dave and Bill went to the movies together to see 2012.Dave and Bill would be the compound subject.
The sentence describes a compound subject, specifically a compound subject of a sentence as it consists of two separate subjects, "Gina" and "Sydney."
Clyde Ormond has written: 'Hunting In The Northwest' 'Bear!' -- subject(s): Bear hunting 'Complete book of outdoor lore' -- subject(s): Natural history, Outdoor life, Outdoor books 'Complete book of hunting' -- subject(s): Hunting
Compound subject: Michelle and Diego Compound predicate: wanted to write poems
No it is not.