Singular:

He is reading a book in the library.The car is parked in front of the house.She is going to the store to buy groceries.The dog is barking loudly at the mailman.My phone is charging on the nightstand.

Plural:

They are studying for their exams together.The students are playing soccer during recess.We are hosting a party at our house this weekend.The birds are singing in the trees outside.Our friends are coming over for dinner tonight.