Is or Are?

Linking Verbs

Linking verbs connect subjects with nouns, pronouns, or adjectives.

Linking verbs can either be plural or singular and they must agrees with the subject of the sentence.

Singular Linking Verbs

When the subject is singular, the linking verb must be singular too. Is and was are singular linking verbs.

"He is a good drummer."

"He was my best friend."

Plural Linking Verbs

When the subject is plural the linking verb must also be plural. Are and were are plural linking verbs.

"They are Italian."

"We were just talking about you."

Note: You always takes the plural form.

Link: I am used to (something)