What are modal auxiliaries?

Modal auxiliaries are helper verbs that change the mood or possibility of an action word, telling you can, must, or might happen.

Think of a normal verb like run. It just says the action is happening. A modal auxiliary is like putting a sticker on that action to show how strong it is. If I say "I run," I am doing it. If I put a can sticker on it, I become able to do it.

Imagine you have a toy car. You can push it gently or shove it hard. Modals tell us how hard the action is pushed.

• Can: This means you have the key. "I can open the door." It is possible and easy.
• Must: This is like being stuck in a seatbelt. You must do it; there is no choice. "I must eat my broccoli."
• Should: This feels like a friendly nudge from a parent. It is a good idea, but not forced. "You should brush your teeth."

Sometimes we are not sure at all. Modals also handle our feelings and uncertainty.

If I say "I will go," it sounds certain. But if I add might, the action becomes wiggly and unsure, like a jelly that is about to fall off a plate. "It might rain" means the sky is thinking about it but hasn't decided yet.

These little words sit right before the main verb to give it its personality. Without them, sentences are flat. With them, they have energy and direction. They help us talk about what is real, what is possible, and what we need to do next.