No. Is is a linking verb, not a preposition, so it works as the main verb connecting a subject to its complement: She is a teacher. Use it whenever you want to say what someone or something is; no other verb is needed.
Situations where this wording fits
No. Is is a linking verb, not a preposition, so it works as the main verb connecting a subject to its complement: She is a teacher. Use it whenever you want to say what someone or something is; no other verb is needed.
If you're naming someone's job or role, is is the only verb you need: My brother is a doctor. It links my brother straight to what he is, so adding another verb would only muddle the sentence.
If you're describing a state or quality, let is carry the meaning itself: The soup is cold. You're not pointing at a place or thing, so is simply connects the subject to the adjective that describes it.
If you're identifying who owns something or who someone is, is still does the linking: This phone is mine. The word after is completes the thought, which is exactly what a linking verb does.
If a preposition seems to follow is, don't rewrite anything: John is in jail. The word in belongs to the phrase in jail, which acts as the complement, while is stays the verb. So a preposition can sit right after is without is ever becoming one.
When a preposition can sit right after 'is'
If another action word follows, is is just helping out, not the verb doing the linking: He is working. There the meaning comes from working, and is only marks the ongoing time. Compare He is tired, where is itself connects him to the description. So check what comes next: a verb after is means it's auxiliary, a description means it's linking.