Learn English – ntransitive verbs such as “arrive” take objects

Are you sure the school is the direct object?

Yes, he is 'going' but he is not 'going his school'. The 'to' means he will eventually end up at school.

An example makes this more apparent: He watched a movie says the movie is what he is watching, but before this he must go to the cinema. The cinema and the movie are different: he goes (intransitive) to the cinema and watches (transitive) the movie.

Hopefully this explains it.

I dreamt a strange dream.

The verb dream can be used as a noun, transitive verb, or intransitive verb. In the above sentence, it's a transitive verb; the subject is I and the direct object is "a strange dream". The sentence, though grammatically correct, sounds old-fashioned. Usually, you say "I had a strange dream.

All his friends laughed at him.

The phrasal verb in the sentence is a transitive verb; the subject is "all his friends and the direct object is "him".

The watch cost nine hundred dollars.

The verb is transitive; the subject is "the watch" and the direct object is nine hundred dollars.