TRANSITIVE AND INTRANSITIVE VERBS

Transitive verbs must have a direct object:

I enjoyed the party (NOT: I enjoyed).

(The subject is 'I', the verb is 'enjoyed' and the direct object is 'the party'.)

William likes chocolate (NOT: William likes).

(The subject is 'William', the verb is 'likes' and the direct object is 'chocolate'.) Intransitive verbs can't have a direct object. Intransitive verbs also can't make a passive.

-They arrived.

(The subject is 'they' and the verb is 'arrived'. There's no object.)

-The children are sleeping.

(The subject is 'the children' and the verb is 'are sleeping'. There's no object.)
Many verbs have a transitive and an intransitive form:

-John ate the pizza (transitive).

-John ate (intransitive).

Also, some verbs that have more than one meaning can be transitive or intransitive depending on which meaning is being used.

-I see the mountains (see = see with your eyes, transitive).

-I see (see = understand, intransitive).