- Use is with singular subjects and are with plural subjects.
- Collective nouns usually take is, but you can use are if you need to emphasize the individuals who belong to the group.
- Phrases like a number of… usually take a plural verb.
When deciding whether to use is or are, look at whether the noun is plural or singular. If the noun is singular, use is. If it is plural or there is more than one noun, use are.