Answer:
The football team ( play / plays ) every Friday night.
The girls in the choir will ( sing / sings ) at the concert this Tuesday.
In the morning, a flock of birds ( fly / flies ) to the pond.
Before school starts, he ( put / puts ) his belongings in his backpack.
Each player on the team needs to ( stretch / stretches ) before the game starts.
Step-by-step explanation:
This can be explained with the subject-verb agreement. If the subject is singular, then the verb must also be singular. If the subject is plural then a plural verb must also be used. The subject and verb must match or agree. Using the example, Mary ( like / likes ) chocolate, Mary would be the subject as the verb is connected to her. Chocolate can't be the subject as the chocolate is not liking, but Mary likes the chocolate.