A linking verb links the subject of the sentence to a noun that names the subject.
In present tense, we use the linking verbs am, is, and are.
I am a girl. She is my mom. We are a family.
In future tense, we use the linking verbs will be.
I will be a doctor when I graduate.
The subject I is linked to the noun doctor, joined with the future tense linking verbs will be.
Here are more examples of future tense linking verbs.
Notice how each sentence uses the linking verbs will be to connect the subject at the beginning of the sentence to a noun that renames the subject.
John will be a scientist.
She will be his assistant.
They will be a team.
Linking verbs connect a subject with a noun that renames the subject. Future tense uses the linking verbs will be.