Helping verbs are always followed by a second verb. They help the main verb to show tense or possibility.
Here are a few examples:
• She had called the police to investigate the matter.
• Roshan was helping his mother in the kitchen.
• We will leave in 10 minutes.
• You should see a doctor.
• I have studied French for 4 years.
Listen to this podcast to know more about the helping verbs.