The predicate is the part of the sentence that tells us what the subject does or is. To put it another way, the predicate is everything that is not the subject.
He stole my bike last week. The bank was robbed last night.
At the heart of the predicate stands a verb or a verb phrase. Along with the verb there may be various direct or indirect objects, adverbials and phrases.
He laughed. – the predicate contains only a verb.
She writes poems. – direct object.
They gave me a gift. – direct and indirect object.
I saw him in the hospital. – adverbial.
When the subject and the predicate are connected with a linking verb, the predicate is either nominal, adjectival or adverbial complement.
He is the president.
These are the candidates.
She is beautiful.
They are careless.
He is in the kitchen.
We are in school.