Imagine you are playing with some toys, and your mommy tells you that you can play with them only if you finish your homework. That "only if" is a modal operator. It is a special word that tells you that you must do something before you can do something else.
In grammar, modal operators are words like "must," "may," "can," "might," "should," "will," and "would." They help us express things like obligation, permission, uncertainty, likelihood, and intention.
For example, when your mommy says, "You must finish your homework," she is using the modal operator "must" to indicate that it's important to do your homework before you can play with toys. Similarly, when she says, "You may play with toys after you finish your homework," the modal operator "may" indicates that she is giving you permission to play with toys once you have finished your homework.
In summary, modal operators are words that help us understand how we relate one event or action to another. They help us communicate important information about what we must do, what we can do, what we should do, and what we want to do.