a10.1. Make sure subject agrees with verb in number (singular or plural) and in person (first, second, third). Problems don't usually arise except in cases when it is not easy to determine whether the subject is singular or plural. Examples: 1. Six employees are enough to handle the project. (Read as "six employees"). 2. Two-thirds of the parts that we'll need to complete the installation are sitting in the truck. (The object of the preposition that follows a subject that's a fraction, such as "two-thirds," determines the verb. So it's "parts are."). 3. All of the original records were lost, but none of the backup files (was,were) affected. ("All" takes plural verb "were" because it refers to an amount. The verb used for "none" depends on what you intend it to mean. Most grammarians reject the view that "none" always means "not one." They say it usually means "not any." If you side with them, use "were." If you don't, use "was."