The verb “to be” is a common helping verb. For example, in the sentence:

“She is studying for her exam.”

The helping verb “is” is used to help form the verb phrase “is studying”.

Some other examples of helping verbs include:

• “have” – “She has finished her homework.”
• “will” – “They will go to the park later.”
• “can” – “I can ride a bike.”
• “may” – “She may join us for dinner.”
• “should” – “You should wear a coat outside.”

Helping verbs work together with main verbs to express tense, voice, or mood. They don’t have full meaning on their own, but rather assist the main verb in conveying the intended meaning.