Answer and explanation:
The subject of a sentence is its topic, what the sentence is about.
When a sentence has two or more subjects, we have what is called a compound subject. Compound subjects are connected by "and" or "or". They can also present commas, when there are more than two subjects.
Let's write the two sentences about people at a party. The compound subjects are underlined:
1. Nadine and I had a lot of fun dancing all night.
2. Jason, Clara, and Chris jumped into the pool at midnight.
Sentence 1 provides us with information about two people: Jason and "I". Sentence 2 provides us with information about three people: Jason, Clara, and Chris.