A predicate is like the second part of a sentence that tells us what the subject is doing, feeling or like. It helps us know more about the subject.
Let's take an example: "Tommy is playing in the park." Here, "Tommy" is our subject and "is playing in the park" is the predicate. It tells us what Tommy is doing - playing in the park.
Sometimes, the predicate can be just a verb. For example: "Kate laughed." Here, "Kate" is the subject and "laughed" is the predicate. It tells us what Kate did - she laughed.
Overall, a predicate is a way to give more detail to the subject in a sentence.