which sentence is correct?

The bike in the bike rack is blue.
The surface of the parking lots were redone this summer.
The sidewalks in the courtyards has been decorated with chalk.
The cars in the parking lot belongs to the teachers.

The correct sentence is: "The bike in the bike rack is blue."

To determine the correct sentence, we need to identify the subject-verb agreement and check for consistency in tense.

Let's examine each sentence:

1. "The bike in the bike rack is blue." - This sentence is correct because the subject "bike" agrees with the singular verb "is," and the tense is consistent.

2. "The surface of the parking lots were redone this summer." - This sentence is incorrect. The subject "surface" is singular, so it should be paired with the singular verb "was," instead of "were" which is plural.

3. "The sidewalks in the courtyards has been decorated with chalk." - This sentence is incorrect. The subject "sidewalks" is plural, so it should be paired with the plural verb "have," instead of "has," which is singular.

4. "The cars in the parking lot belongs to the teachers." - This sentence is incorrect. The subject "cars" is plural, so it should be paired with the plural verb "belong," instead of "belongs," which is singular.

Remember, when checking for subject-verb agreement, make sure the verb matches the number (singular or plural) of the subject.

Here are the subjects:

bike
surface
sidewalks
cars

Two are singular. Two are plural.
Find the verb that matches the subject in its sentence.