A singular subject takes a singular verb; a plural subject takes a plural verb.

Examples:

Electromagnetic radiation travels as waves.

Radio and TV signals are transmitted on carrier waves.

The number of the subject is not changed by a phrase or a clause that separates the subject from the verb.

Examples:

Radio waves with short wavelengths penetrate the atmosphere and are used to communicate with spacecraft.

The ozone layer, which has holes, absorbs most of the ultraviolet radiation in sunlight.

Television, along with radio, is considered one of the most powerful mass media.

Television sets with high definition give clear and crisp pictures.

Indefinite pronouns like each, either, neither, one, everybody, no one, nobody, anybody, someone, and somebody are singular and use singular verbs.

These pronouns are used when not refering to a particular person, place, or thing.

Examples:

Each of my male classmates has a toy robot.

No one believes that robots will replace humankind someday.

The words many, both, and several use plural verbs. The phrase a few also uses plural verbs.

Example:

Rogun Dam in Tajikistan has a height of 335 meters. Vojun Dam in Italy has a height of 262 meters. Both are impressive structures.

The following types of special nouns ending in -s use singular verbs.

• Names of diseases like measles and mumps

• Subjects of study such as economics, physics, civics, mathematics, and statistics

• Games such as checkers and chess

• Names of countries like the United States, Philippines, Honduras

• Words thought of as a unit like news and molasses

Examples:

Measles has spread out like a plague.

Checkers is a famous game among the Chinese.