Helping verbs, also known as auxiliary verbs, are used in conjunction with main verbs to express tense, mood, voice, or emphasis in a sentence. They help to clarify the meaning of the main verb and provide additional information about the action or state of being.

Here are some examples of helping verbs and how they are used in a sentence:

1. “I am studying for my exam.” (The helping verb “am” is used to indicate the present progressive tense.)

2. “She has finished her homework.” (The helping verb “has” is used to indicate the present perfect tense.)

3. “They will go to the party.” (The helping verb “will” is used to indicate future tense.)

4. “He should have called me.” (The helping verbs “should” and “have” are used to indicate obligation and past perfect tense, respectively.)

5. “We can swim in the pool.” (The helping verb “can” is used to indicate ability or permission.)

6. “The cake was baked by my mom.” (The helping verb “was” is used to indicate passive voice.)

In these examples, the helping verbs work together with the main verbs (studying, finished, go, called, swim, baked) to convey different meanings and nuances in the sentences.