Respuesta :
Answer:
The castle was gray
My horse doesn't like to run
The envelope is over there
Mark learned about the civil war
Explanation:
A singular noun represents just one person, place, or thing. The sentences that contain a common singular noun are;
- The castle was gray
- My horse doesn't like to run.
- The envelope is over there.
- Mark learned about the Civil War.
In each of the sentences given above, we find that the noun, which is the name of an animal, place, or thing is just one or singular. In the options not included, the plural forms of the nouns are used.
Therefore, the options above are singular nouns.
Learn more here:
https://brainly.com/question/12092554