transitive verbs : take a diretc object (i saw her/ they ate pasta/ he wrote a letter). Transitive verbs not always used with a d.o....(they ate quickly/ he wrote to her), but if they can be , the verb is defined as transitive.

intransitive verbs: Verbs which can never be used with a D.o. (Mary arrived late/ i lay down)

Passive verbs (only transitive verbs are used in the passive)